--_OVID_emlbndry_WKHLTH Content-Type: text/plain <1> UI - 2008-310VG-0001 DD - ISI Document Solution: 310VG AU - Kirchhoff H MA - kirchhh@uni-muenster.de RA - Kirchhoff H TI - Molecular crowding and order in photosynthetic membranes [Review] SO - Trends in Plant Science. 13(5):201-207, 2008 May. AS - Trends Plant Sci 2008 May;13(5):201-207 PU - ELSEVIER SCIENCE LONDON, 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND. URL: http://www.epress.co.uk/ IS - 1360-1385 MH - Higher-plant chloroplast MH - Photosystem-ii MH - Thylakoid membranes MH - Plastoquinone compartmentation MH - Lipid-composition MH - Green plants MH - Organization MH - Grana MH - Architecture MH - Diffusion. AB - The integrity and maintenance of the photosynthetic apparatus in thylakoid membranes of higher plants requires lateral mobility of their components between stacked grana thylakoids and unstacked stroma lamellae. Computer simulations based on realistic protein densities suggest serious problems for lateral protein and plastoquinone diffusion especially in grana membranes, owing to strong retardation by protein complexes. It has been suggested that three structural features of grana thylakoids ensure efficient lateral transport: the organization of protein complexes into supercomplexes; the arrangement of supercomplexes into structured assemblies, which facilitates diffusion process in crowded membranes; the limitation of the diameter of grana discs to less than similar to 500 nm, which keeps diffusion times short enough to support regulation of light harvesting and repair of photodamaged photosystem II. [References: 36] LG - English PT - Review SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Kirchhoff H Inst Bot Schlossgarten 3 D-48149 Munster Germany Inst Bot D-48149 Munster Germany <2> UI - 2008-310CS-0008 DD - ISI Document Solution: 310CS AU - Boussadia O AU - Ben Mariem F AU - Mechri B AU - Boussetta W AU - Braham M AU - El Hadj SB MA - boussadio@yahoo.fr RA - Boussadia O TI - Response to drought of two olive tree cultivars (cv Koroneki and Meski) SO - Scientia Horticulturae. 116(4):388-393, 2008 May 20. AS - Sci. Hortic 2008 May 20;116(4):388-393 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.com IS - 0304-4238 MH - Chlorophyll fluorescence MH - Drought stress MH - Gas exchange MH - Leaf water potential MH - Olea europaea. MH - Net co2 assimilation MH - Photosynthetic electron-transport MH - Chlorophyll fluorescence MH - Photosystem-ii MH - Field conditions MH - Water relations MH - Gas-exchange MH - Light stress MH - Xanthophyll cycle MH - Mild drought. AB - The effect of water deprivation on plant water status, photosynthetic gas exchange and fluorescence parameters in two different olive tree varieties (Olea europaea L. var. 'koroneiki', 'Meski') was studied. Two-year-old olive trees, grown in pots in greenhouse, were subjected to one of three drought treatments (i.e., mild, moderate and severe drought stress) and compared to control trees. Both the leaf water potential (Psi(w)) and the relative water content (RWC) of the two varieties decreased with increasing levels of drought stress. Koroneiki showed higher (less negative) values of Psi(w) and lower values of RWC than the Meski, particularly during severe drought stress. Net photosynthetic assimilation and stomatal conductance declined with drought. This inactivation of photosynthetic activity was accompanied by changes in the fluorescence characteristics. The PSII maximal photochemical efficiency (F-v/F-m), the intrinsic efficiency of open PSII reaction centres (F-v'/F-m'), the photochemical efficiency of PSII (Phi(PSII)) and the total electron flow (J(t)) decreased during the development of drought stress. The non-quenching photochimique (q(N)) showed an increase in the response to water deficit. These observations are discussed in relation to the strategies developed to grow drought-resistant olive trees in and areas. (c) 2008 Elsevier B.V. All rights reserved. [References: 46] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Boussadia O Inst Natl Agron Tunisie 43 Ave Charlnicol,1082 Cite El Maharajen Tunis Tunisia Inst Natl Agron Tunisie Tunis Tunisia Inst Olivier Sousse Sousse 4061 Tunisia <3> UI - 2008-310IP-0010 DD - ISI Document Solution: 310IP AU - Sfichi-Duke L AU - Ioannidis NE AU - Kotzabasis K MA - kotzab@biology.uoc.gr RA - Kotzabasis K TI - Fast and reversible response of thylakoid-associated polyamines during and after UV-B stress: a comparative study of the wild type and a mutant lacking chlorophyll b of unicellular green alga Scenedesmus obliquus SO - Planta. 228(2):341-353, 2008 Jul. AS - Planta 2008 Jul;228(2):341-353 PU - SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA. URL: http://www.springeronline.com IS - 0032-0935 MH - Light-harvesting complex MH - Chlorophyll fluorescence MH - Carotenoids MH - Polyamines MH - Scenedesmus obliquus MH - Ultraviolet-b radiation. MH - Ii reaction-center MH - Harvesting complex-ii MH - Photosystem-ii MH - Photosynthetic apparatus MH - Chlamydomonas-reinhardtii MH - Dunaliella-tertiolecta MH - Ultraviolet-radiation MH - Energy-dissipation MH - Protein complexes MH - Beta-carotene. AB - The functional and biochemical aspects of the photosynthetic apparatus in response to UV-B radiation were examined in unicellular oxygenic algae Scenedesmus obliquus. The wild type (Wt) and a chlorophyll b-less mutant (Wt-lhc) were used as a specific tool for the understanding of antenna role. Photosynthesis was monitored during and after UV-B stress by time resolved fluorescence spectroscopy and polarography. Carotenoids, such as neoxanthin, loroxanthin, lutein, violaxanthin, antheraxanthin, zeaxanthin, alpha- and beta-carotene, cellular and thylakoid-associated putrescine, spermidine, spermine and subcomplexes of light-harvesting complex (LHCII) of photosystem II (PSII) were investigated to assess their possible involvement in response to UV-B. Oxygen evolution depression by UV-B was higher in the Wt-lhc mutant than in the Wt. Photosynthesis recovery occurred in the Wt, but not in the mutant. The dissipation of excess excitation energy during UV-B stress was accompanied by changes in the thylakoid-associated polyamines which were much higher than changes in xanthophylls. We conclude that, at least in the unicellular green alga S. obliquus, mutants lacking chlorophyll b have significant lower capacity for recovery after UV-B stress. In addition, the comparison of xanthophylls and thylakoid-associated polyamines reveals that the latter are more responsive to UV-B stress and in a reversible manner. [References: 72] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Kotzabasis K Univ Crete, Dept Biol POB 2208 Iraklion 71409 Greece Univ Crete, Dept Biol Iraklion 71409 Greece <4> UI - 2008-310OP-0003 DD - ISI Document Solution: 310OP AU - Sawada H AU - Shim IS AU - Usui K AU - Kobayashi K AU - Fujihara S MA - hiros2l6@affrc.go.jp RA - Sawada H TI - Adaptive mechanism of Echinochloa crus-galli Beauv. var. formosensis Ohwi under salt stress: Effect of salicylic acid on salt sensitivity SO - Plant Science. 174(6):583-589, 2008 Jun. AS - Plant Sci 2008 Jun;174(6):583-589 PU - ELSEVIER IRELAND LTD, ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND. URL: http://www.elsevier.nl IS - 0168-9452 MH - Catalase MH - Echinochloa crus-galli MH - Hydrogen peroxide MH - Oxidative stress MH - Salicylic acid MH - Salt stress. MH - Oryza-sativa l. MH - Systemic acquired-resistance MH - Oxidative stress MH - Tobacco plants MH - C-3 plants MH - Cell-death MH - Seedlings MH - Rice MH - Accumulation MH - Responses. AB - our previous study revealed that salicylic acid (SA) accumulates in salt-stressed rice (Oryza sativa L. cv. Nipponbare) seedlings, and we hypothesized that the accumulation of SA might potentiate oxidative injury in rice seedlings since the inhibition of SA synthesis alleviated the growth inhibition under high salinity. To further clarify the action of SA under salt stress, we investigated the changes in the SA content, the activities of the antioxidative enzymes, and the effects of exogenous SA on barnyardgrass (Echinochloa crus-galli Beauv. var. formosensis Ohwi), a gramineous weed which shows lower SA content and is more salt tolerant than rice. In E. crus-galli seedlings exposed to high salinity, neither free nor conjugated SA content showed any increase, while the fresh weight of the shoot and chlorophyll fluorescence (Phi(PS11)) slightly decreased. When E. crus-galli seedlings were treated with salt after foliar application of SA, the absorbed SA resulted in the enhancement of the salt-induced growth inhibition and a striking reduction of the Phi(PS11) value. Catalase (CAT) and superoxide dismutase (SOD) activities of E. crus-galli seedlings were induced by the salt treatment. However, SA pre-treatment suppressed such an induction of CAT activity and further promoted SOD activity, both of which led to the elevation of the leaf hydrogen peroxide (H2O2) level. The present results suggested that enlargement of the cellular SA pool facilitates the generation of H2O2 through the suppression of CAT activity and through a remarkable promotion of SOD activity, and thereby enhances the oxidative injury caused by salt stress. (C) 2008 Elsevier Ireland Ltd. All rights reserved. [References: 43] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Sawada H Natl Agr Res Ctr, Res Team Sol & Plant Anal 3-1-1 Kannandai Tsukuba Ibaraki 3058666 Japan Natl Agr Res Ctr, Res Team Sol & Plant Anal Tsukuba Ibaraki 3058666 Japan Univ Tsukuba, Grad Sch Life & Environm Sci Tsukuba 3058572 Japan Univ Seoul, Dept Environm Hort Seoul 130743 South Korea <5> UI - 2008-310OP-0004 DD - ISI Document Solution: 310OP AU - Guidi L AU - Degl'lnnocenti E MA - guidilu@agr.unipi.it RA - Guidi L TI - Ozone effects on high light-induced photoinhibition in Phaseolus vulgaris SO - Plant Science. 174(6):590-596, 2008 Jun. AS - Plant Sci 2008 Jun;174(6):590-596 PU - ELSEVIER IRELAND LTD, ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND. URL: http://www.elsevier.nl IS - 0168-9452 MH - Bean MH - Chlorophyll fluorescence imaging MH - Ozone MH - Photoinhibition MH - Photosynthesis. MH - Photosynthetic electron-transport MH - Leaf chlorophyll fluorescence MH - Photosystem-ii MH - A fluorescence MH - Quantum yield MH - Water-stress MH - Elevated co2 MH - In-vivo MH - Leaves MH - Exposure. AB - In this study the response to photoinhibition of photosynthesis and subsequent recovery was examined in plants of Phaseolus vulgaris L. cultivar 'Pinto' exposed to charcoal-filtered air or to ozone (O-3) at 150 nL L-1 either for 3 h, or for 5 h. The responses were analysed using chlorophyll fluorescence imaging and by conventional fluorometry. Compared to control plants maintained in charcoal-filtered air, in plants exposed for 3 h to O-3 and then subjected to high light treatment, the results show an increased tolerance to photoinhibition. Plants exposed to the same O-3 concentration but for the longer 5-h period, were not tolerant to the photoinhibition treatment and, instead showed visible symptoms of damage (chlorosis and necrosis) clearly attributable to the longer O-3 exposure. Here the detrimental effects of O-3 aggravated the effects of the high light photoinhibitory treatment. The leaves exposed to the shorter O-3 treatment (150 nL L-1 for 3 h) developed an ability to counteract the negative effects of a high light exposure probably because the O-3 had activated an antioxidant system able to protect the photosynthetic machinery. (C) 2008 Elsevier Ireland Ltd. All rights reserved. [References: 52] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Guidi L Dipartimento Chim & Biotecnol Agr Via Borghetto 80 I-56124 Pisa Italy Dipartimento Chim & Biotecnol Agr I-56124 Pisa Italy <6> UI - 2008-310OP-0006 DD - ISI Document Solution: 310OP AU - Li MJ AU - Ma FW AU - Zhang M AU - Pu F MA - fwm64@sina.com RA - Ma FW TI - Distribution and metabolism of ascorbic acid in apple fruits (Malus domestica Borkh cv. Gala) SO - Plant Science. 174(6):606-612, 2008 Jun. AS - Plant Sci 2008 Jun;174(6):606-612 PU - ELSEVIER IRELAND LTD, ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND. URL: http://www.elsevier.nl IS - 0168-9452 MH - Apple fruits MH - Ascorbic acid MH - Distribution MH - Metabolism. MH - Gamma-lactone dehydrogenase MH - Arabidopsis-thaliana MH - Vitamin-c MH - Xanthophyll cycle MH - Biosynthesis MH - Plants MH - Glutathione MH - Pathway MH - Accumulation MH - Phloem. AB - The objective of this study was to determine ascorbic acid (AsA) distribution, biosynthesis and recycling in different tissues of young and mature fruit of cv. Gala apple (Malus domestica Borkh). Our results showed that the peel of 'Gala' apple had the highest AsA levels among all the tissue types, which resulted from a combination of, lower ascorbate peroxidase (APX, EC 1.11.1.11) activity consuming AsA, and higher dehydroascorbate reductase (DHAR, EC 1.8.5.1) and monodehydroascorbate reductase (MDHAR, EC 1.6.5.4) activities used to recycle AsA. Exogenous feeding of AsA synthesis precursors demonstrated that the peel was capable of de nono AsA biosynthesis via L-galactose and D-galacturonic acid pathways whereas the flesh and seed were only able to synthesize AsA via L-galactose pathway. The young fruit had higher AsA concentration and stronger capability of AsA biosynthesis and recycling. The sun-exposed peel had higher AsA concentration and stronger capability of recycling AsA than the shaded peel, while there was no difference in the flesh between the sun-exposed side and the shaded side. Abundant AsA was found in fruit vascular tissue, which suggests that AsA can be transported to vascular tissues of fruit or vascular tissues could synthesize AsA itself in 'Gala' apple. (C) 2008 Elsevier Ireland Ltd. All rights reserved. [References: 39] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Ma FW NW A&F Univ, Coll Hort Yangling 712100 Shaanxi Peoples R China NW A&F Univ, Coll Hort Yangling 712100 Shaanxi Peoples R China <7> UI - 2008-308TF-0028 DD - ISI Document Solution: 308TF AU - Sasaki K AU - Mito K AU - Ohara K AU - Yamamoto H AU - Yazaki K MA - yazaki@rish.kyoto-u.ac.jp RA - Yazaki K TI - Cloning and characterization of naringenin 8-prenyltransferase, a flavonoid-specific prenyltransferase of Sophora flavescens SO - Plant Physiology. 146(3):1075-1084, 2008 Mar. AS - Plant Physiol 2008 Mar;146(3):1075-1084 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Synechocystis sp pcc-6803 MH - Prenylated flavonoids MH - Homogentisate phytyltransferase MH - Cdna cloning MH - Methyl jasmonate MH - Var angustifolia MH - Gene-expression MH - Cultured-cells MH - Norway spruce MH - Key enzyme. AB - Prenylated flavonoids are natural compounds that often represent the active components in various medicinal plants and exhibit beneficial effects on human health. Prenylated flavonoids are hybrid products composed of a flavonoid core mainly attached to either 5-carbon (dimethylallyl) or 10-carbon (geranyl) prenyl groups derived from isoprenoid (terpenoid) metabolism, and the prenyl groups are crucial for their biological activity. Prenylation reactions in vivo are crucial coupling processes of two major metabolic pathways, the shikimate-acetate and isoprenoid pathways, in which these reactions are also known as a rate- limiting step. However, none of the genes responsible for the prenylation of flavonoids has been identified despite more than 30 years of research in this field. We have isolated a prenyltransferase gene from Sophora flavescens, SfN8DT-1, responsible for the prenylation of the flavonoid naringenin at the 8-position, which is specific for flavanones and dimethylallyl diphosphate as substrates. Phylogenetic analysis shows that SfN8DT-1 has the same evolutionary origin as prenyltransferases for vitamin E and plastoquinone. The gene expression of SfN8DT-1 is strictly limited to the root bark where prenylated flavonoids are solely accumulated in planta. The ectopic expression of SfN8DT-1 in Arabidopsis thaliana resulted in the formation of prenylated apigenin, quercetin, and kaempferol, as well as 8-prenylnaringenin. SfN8DT-1 represents the first flavonoid-specific prenyltransferase identified in plants and paves the way for the identification and characterization of further genes responsible for the production of this large and important class of secondary metabolites. [References: 42] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Yazaki K Kyoto Univ, Res Inst Sustainable Humanosphere, Lab Plant Gene Express Uji 6110011 Japan Kyoto Univ, Res Inst Sustainable Humanosphere, Lab Plant Gene Express Uji 6110011 Japan Toyo Univ, Fac Life Sci, Plant Regulat Res Ctr Gunma 3740193 Japan <8> UI - 2008-308TF-0048 DD - ISI Document Solution: 308TF AU - Li FQ AU - Vallabhaneni R AU - Wurtzel ET MA - wurtzel@lehman.cuny.edu RA - Wurtzel ET TI - PSY3, a new member of the phytoene synthase gene family conserved in the poaceae and regulator of abiotic stress-induced root carotenogenesis SO - Plant Physiology. 146(3):1333-1345, 2008 Mar. AS - Plant Physiol 2008 Mar;146(3):1333-1345 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Abscisic-acid biosynthesis MH - 9-cis-epoxycarotenoid dioxygenase MH - Escherichia-coli MH - Zeaxanthin epoxidase MH - Water-stress MH - Nicotiana-plumbaginifolia MH - Carotenoid accumulation MH - Aba 8'-hydroxylases MH - Osmotic-stress MH - Key enzyme. AB - Abscisic acid (ABA) plays a vital role in mediating abiotic stress responses in plants. De novo ABA biosynthesis involves cleavage of carotenoid precursors by 9-cis-epoxycarotenoid dioxygenase (NCED), which is rate controlling in leaves and roots; however, additional bottlenecks in roots must be overcome, such as biosynthesis of upstream carotenoid precursors. Phytoene synthase (PSY) mediates the first committed step in carotenoid biosynthesis; with PSY3 described here, maize (Zea mays) and other members of the Poaceae have three paralogous genes, in contrast to only one in Arabidopsis thaliana. PSY gene duplication has led to subfunctionalization, with each paralog exhibiting differential gene expression. We showed that PSY3 encodes a functional enzyme for which maize transcript levels are regulated in response to abiotic stresses, drought, salt, and ABA. Drought-stressed roots showed elevated PSY3 transcripts and ABA, responses reversed by rehydration. By blocking root carotenoid biosynthesis with the maize y9 mutation, we demonstrated that PSY3 mRNA elevation correlates with carotenoid accumulation and that blocking carotenoid biosynthesis interferes with stress-induced ABA accumulation. In parallel, we observed elevated NCED transcripts and showed that, in contrast to dicots, root zeaxanthin epoxidase transcripts were unchanged. PSY3 was the only paralog for which transcripts were induced in roots and abiotic stress also affected leaf PSY2 transcript levels; PSY1 mRNA was not elevated in any tissues tested. Our results suggest that PSY3 expression influences root carotenogenesis and defines a potential bottleneck upstream of NCED; further examination of PSY3 in the grasses is of value for better understanding root-specific stress responses that impact plant yield. [References: 48] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Wurtzel ET CUNY Herbert H Lehman Coll, Dept Biol Sci Bronx, NY 10468 USA CUNY Herbert H Lehman Coll, Dept Biol Sci Bronx, NY 10468 USA CUNY, Univ Ctr New York, NY 10016 USA <9> UI - 2008-308TF-0051 DD - ISI Document Solution: 308TF AU - Toh S AU - Imamura A AU - Watanabe A AU - Nakabayashi K AU - Okamoto M AU - Jikumaru Y AU - Hanada A AU - Aso Y AU - Ishiyama K AU - Tamura N AU - Iuchi S AU - Kobayashi M AU - Yamaguchi S AU - Kamiya Y AU - Nambara E AU - Kawakami N MA - kawakami@isc.meiji.ac.jp RA - Kawakami N TI - High temperature-induced abscisic acid biosynthesis and its role in the inhibition of gibberellin action in Arabidopsis seeds SO - Plant Physiology. 146(3):1368-1385, 2008 Mar. AS - Plant Physiol 2008 Mar;146(3):1368-1385 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - 9-cis-epoxycarotenoid dioxygenase gene MH - Lettuce lactuca-sativa MH - Zeaxanthin epoxidase gene MH - Nicotiana-plumbaginifolia MH - Negative regulator MH - Signal-transduction MH - Aldehyde oxidase MH - Phytochrome regulation MH - Functional-analysis MH - Response pathways. AB - Suppression of seed germination at supraoptimal high temperature (thermoinhibiton) during summer is crucial for Arabidopsis ( Arabidopsis thaliana) to establish vegetative and reproductive growth in appropriate seasons. Abscisic acid (ABA) and gibberellins (GAs) are well known to be involved in germination control, but it remains unknown how these hormone actions (metabolism and responsiveness) are altered at high temperature. Here, we show that ABA levels in imbibed seeds are elevated at high temperature and that this increase is correlated with up-regulation of the zeaxanthin epoxidase gene ABA1/ZEP and three 9-cis-epoxycarotenoid dioxygenase genes, NCED2, NCED5, and NCED9. Reverse-genetic studies show that NCED9 plays a major and NCED5 and NCED2 play relatively minor roles in high temperature-induced ABA synthesis and germination inhibition. We also show that bioactive GAs stay at low levels at high temperature, presumably through suppression of GA 20-oxidase genes, GA20ox1, GA20ox2, and GA20ox3, and GA 3-oxidase genes, GA3ox1 and GA3ox2. Thermoinhibition-tolerant germination of loss-of-function mutants of GA negative regulators, SPINDLY ( SPY) and RGL2, suggests that repression of GA signaling is required for thermoinibition. Interestingly, ABA-deficient aba2-2 mutant seeds show significant expression of GA synthesis genes and repression of SPY expression even at high temperature. In addition, the thermoinhibition-resistant germination phenotype of aba2-1 seeds is suppressed by a GA biosynthesis inhibitor, paclobutrazol. We conclude that high temperature stimulates ABA synthesis and represses GA synthesis and signaling through the action of ABA in Arabidopsis seeds. [References: 94] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Kawakami N Meiji Univ, Sch Agr, Dept Life Sci Kanagawa 2148571 Japan Meiji Univ, Sch Agr, Dept Life Sci Kanagawa 2148571 Japan RIKEN Plant Sci Ctr, Growth Regulat Res Grp Kanagawa 2300045 Japan RIKEN Bioresource Ctr, Expt Plant Div Tsukuba Ibaraki 3050074 Japan <10> UI - 2008-308VJ-0002 DD - ISI Document Solution: 308VJ AU - Covshoff S AU - Majeran W AU - Liu P AU - Kolkman JM AU - van Wijk KJ AU - Brutnell TP MA - tpb8@cornell.edu RA - Brutnell TP TI - Deregulation of maize C-4 photosynthetic development in a mesophyll cell-defective mutant SO - Plant Physiology. 146(4):1469-1481, 2008 Apr. AS - Plant Physiol 2008 Apr;146(4):1469-1481 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Bundle-sheath-cells MH - Zea-mays-l MH - Gene-expression MH - Photosystem-ii MH - Phosphoenolpyruvate carboxylase MH - Arabidopsis-thaliana MH - Differential expression MH - Calvin cycle MH - Chloroplasts MH - Leaves. AB - During maize (Zea mays) C-4 differentiation, mesophyll (M) and bundle sheath (BS) cells accumulate distinct sets of photosynthetic enzymes, with very low photosystem II (PSII) content in BS chloroplasts. Consequently, there is little linear electron transport in the BS and ATP is generated by cyclic electron flow. In contrast, M thylakoids are very similar to those of C-3 plants and produce the ATP and NADPH that drive metabolic activities. Regulation of this differentiation process is poorly understood, but involves expression and coordination of nuclear and plastid genomes. Here, we identify a recessive allele of the maize high chlorophyll fluorescence (Hcf136) homolog that in Arabidopsis (Arabidopsis thaliana) functions as a PSII stability or assembly factor located in the thylakoid lumen. Proteome analysis of the thylakoids and electron microscopy reveal that Zmhcf136 lacks PSII complexes and grana thylakoids in M chloroplasts, consistent with the previously defined Arabidopsis function. Interestingly, hcf136 is also defective in processing the full-length psbB-psbT-psbH-petB-petD polycistron specifically in M chloroplasts. To determine whether the loss of PSII in M cells affects C-4 differentiation, we performed cell-type-specific transcript analysis of hcf136 and wild-type seedlings. The results indicate that M and BS cells respond uniquely to the loss of PSII, with little overlap in gene expression changes between data sets. These results are discussed in the context of signals that may drive differential gene expression in C-4 photosynthesis. [References: 65] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Brutnell TP Cornell Univ, Dept Plant Biol Ithaca, NY 14853 USA Cornell Univ, Dept Plant Biol Ithaca, NY 14853 USA Cornell Univ, Boyce Thompson Inst Plant Res Ithaca, NY 14853 USA Iowa State Univ, Dept Stat Ames, IA 50011 USA <11> UI - 2008-308VJ-0003 DD - ISI Document Solution: 308VJ AU - Lu Y AU - Savage LJ AU - Ajjawi I AU - Imre KM AU - Yoder DW AU - Benning C AU - DellaPenna D AU - Ohlrogge JB AU - Osteryoung KW AU - Weber AP AU - Wilkerson CG AU - Last RL MA - lastr@msu.edu RA - Last RL TI - New connections across pathways and cellular processes: Industrialized mutant screening reveals novel associations between diverse phenotypes in Arabidopsis SO - Plant Physiology. 146(4):1482-1500, 2008 Apr. AS - Plant Physiol 2008 Apr;146(4):1482-1500 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Saccharomyces-cerevisiae genome MH - Ascorbic-acid MH - Gene-expression MH - Glycerol-3-phosphate acyltransferase MH - Chloroplast division MH - Functional genomics MH - Systems biology MH - Plant-systems MH - Ms/ms assay MH - Thaliana. AB - In traditional mutant screening approaches, genetic variants are tested for one or a small number of phenotypes. Once bona fide variants are identified, they are typically subjected to a limited number of secondary phenotypic screens. Although this approach is excellent at finding genes involved in specific biological processes, the lack of wide and systematic interrogation of phenotype limits the ability to detect broader syndromes and connections between genes and phenotypes. It could also prevent detection of the primary phenotype of a mutant. As part of a systems biology approach to understand plastid function, large numbers of Arabidopsis thaliana homozygous T-DNA lines are being screened with parallel morphological, physiological, and chemical phenotypic assays (www.plastid.msu.edu). To refine our approaches and validate the use of this high-throughput screening approach for understanding gene function and functional networks, approximately 100 wild-type plants and 13 known mutants representing a variety of phenotypes were analyzed by a broad range of assays including metabolite profiling, morphological analysis, and chlorophyll fluorescence kinetics. Data analysis using a variety of statistical approaches showed that such industrial approaches can reliably identify plant mutant phenotypes. More significantly, the study uncovered previously unreported phenotypes for these well-characterized mutants and unexpected associations between different physiological processes, demonstrating that this approach has strong advantages over traditional mutant screening approaches. Analysis of wild-type plants revealed hundreds of statistically robust phenotypic correlations, including metabolites that are not known to share direct biosynthetic origins, raising the possibility that these metabolic pathways have closer relationships than is commonly suspected. [References: 72] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Last RL Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Plant Biol E Lansing, MI 48824 USA <12> UI - 2008-308VJ-0009 DD - ISI Document Solution: 308VJ AU - Kirchhoff H AU - Haferkamp S AU - Allen JF AU - Epstein DBA AU - Mullineaux CW MA - kirchhh@uni-muenster.de RA - Kirchhoff H TI - Protein diffusion and macromolecular crowding in thylakoid membranes SO - Plant Physiology. 146(4):1571-1578, 2008 Apr. AS - Plant Physiol 2008 Apr;146(4):1571-1578 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Light-harvesting complex MH - Photosystem-ii MH - Lateral diffusion MH - Higher-plants MH - Dependence MH - Mobility MH - Photosynthesis MH - Organization MH - Architecture MH - Spinach. AB - The photosynthetic light reactions of green plants are mediated by chlorophyll-binding protein complexes located in the thylakoid membranes within the chloroplasts. Thylakoid membranes have a complex structure, with lateral segregation of protein complexes into distinct membrane regions known as the grana and the stroma lamellae. It has long been clear that some protein complexes can diffuse between the grana and the stroma lamellae, and that this movement is important for processes including membrane biogenesis, regulation of light harvesting, and turnover and repair of the photosynthetic complexes. In the grana membranes, diffusion may be problematic because the protein complexes are very densely packed (approximately 75% area occupation) and semicrystalline protein arrays are often observed. To date, direct measurements of protein diffusion in green plant thylakoids have been lacking. We have developed a form of fluorescence recovery after photobleaching that allows direct measurement of the diffusion of chlorophyll-protein complexes in isolated grana membranes from Spinacia oleracea. We show that about 75% of fluorophores are immobile within our measuring period of a few minutes. We suggest that this immobility is due to a protein network covering a whole grana disc. However, the remaining fraction is surprisingly mobile (diffusion coefficient 4.6 +/- 0.4 x 10(-11) cm(2) s(-1)), which suggests that it is associated with mobile proteins that exchange between the grana and stroma lamellae within a few seconds. Manipulation of the protein-lipid ratio and the ionic strength of the buffer reveals the roles of macromolecular crowding and protein-protein interactions in restricting the mobility of grana proteins. [References: 29] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Kirchhoff H Inst Bot D-48149 Munster Germany Inst Bot D-48149 Munster Germany Queen Mary Univ London, Sch Biol & Chem Sci London E1 4NS England Univ Warwick, Math Inst Coventry CV4 7AL W Midlands England <13> UI - 2008-308VJ-0034 DD - ISI Document Solution: 308VJ AU - Wodala B AU - Deak Z AU - Vass I AU - Erdei L AU - Altorjay I AU - Horvath F MA - horvathf@bio.u-szeged.hu RA - Horvath F TI - In vivo target sites of nitric oxide in photosynthetic electron transport as studied by chlorophyll fluorescence in pea leaves SO - Plant Physiology. 146(4):1920-1927, 2008 Apr. AS - Plant Physiol 2008 Apr;146(4):1920-1927 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Ii reaction center MH - Non-heme iron MH - Photosystem-ii MH - Xanthophyll cycle MH - Reversible inhibition MH - Sodium-nitroprusside MH - Disease resistance MH - Plant-mitochondria MH - Redox components MH - Nitrosyl adducts. AB - The role of nitric oxide (NO) in photosynthesis is poorly understood as indicated by a number of studies in this field with often conflicting results. As various NO donors may be the primary source of discrepancies, the aim of this study was to apply a set of NO donors and its scavengers, and examine the effect of exogenous NO on photosynthetic electron transport in vivo as determined by chlorophyll fluorescence of pea (Pisum sativum) leaves. Sodium nitroprusside-induced changes were shown to be mediated partly by cyanide, and S-nitroso-N-acetylpenicillinamine provided low yields of NO. However, the effects of S-nitrosoglutathione are inferred exclusively by NO, which made it an ideal choice for this study. QA(-) reoxidation kinetics show that NO slows down electron transfer between Q(A) and Q(B), and inhibits charge recombination reactions of Q(A)(-) with the S-2 state of the water-oxidizing complex in photosystem II. Consistent with these results, chlorophyll fluorescence induction suggests that NO also inhibits steady-state photochemical and nonphotochemical quenching processes. NO also appears to modulate reaction-center-associated nonphotochemical quenching. [References: 41] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Horvath F Univ Szeged, Dept Plant Physiol H-6701 Szeged Hungary Univ Szeged, Dept Plant Physiol H-6701 Szeged Hungary Hungarian Acad Sci, Biol Res Ctr, Inst Plant Biol H-6701 Szeged Hungary Debrecen Univ Med, Dept Gastroenterol, Med & Hlth Sci Ctr H-4001 Debrecen Hungary <14> UI - 2008-308VV-0015 DD - ISI Document Solution: 308VV AU - Drath M AU - Kloft N AU - Batschauer A AU - Marin K AU - Novak J AU - Forchhammer K MA - karl.forchhammer@unituebingen.de RA - Forchhammer K TI - Ammonia triggers photodamage of photosystem II in the cyanobacterium Synechocystis sp strain PCC 6803 SO - Plant Physiology. 147(1):206-215, 2008 May. AS - Plant Physiol 2008 May;147(1):206-215 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Oxygen-evolving complex MH - Chlorophyll fluorescence MH - Electron-transport MH - Water oxidation MH - Ftsh protease MH - Light stress MH - Pcc 6803 MH - Photoinhibition MH - Manganese MH - Mechanism. AB - Ammonia has long been known to be toxic for many photosynthetic organisms; however, the target for its toxicity remains elusive. Here, we show that in the cyanobacterium Synechocystis sp. strain PCC 6803, ammonia triggers a rapid photodamage of photosystem II (PSII). Whereas wild-type cells can cope with this damage by turning on the FtsH2-dependent PSII repair cycle, the FtsH2-deficient mutant is highly sensitive and loses PSII activity at millimolar concentration of ammonia. Ammonia-triggered PSII destruction is light dependent and occurs already at low photon fluence rates. Experiments with monochromatic light showed that ammonia-promoted PSII photoinhibition is executed by wavebands known to directly destroy the manganese cluster in the PSII oxygen-evolving complex, suggesting that the oxygen-evolving complex may be a direct target for ammonia toxicity. [References: 37] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Forchhammer K Univ Giessen, Inst Mikrobiol & Mol Biol D-35392 Giessen Germany Univ Giessen, Inst Mikrobiol & Mol Biol D-35392 Giessen Germany Univ Marburg, Fachbereich Biol Mol Pflanzenphysiol D-35032 Marburg Germany Univ Cologne, Inst Biochem D-50674 Cologne Germany Univ Tubingen, Lehrstuhl Mikrobiol Organism Interakt D-72076 Tubingen Germany <15> UI - 2008-308VV-0026 DD - ISI Document Solution: 308VV AU - Yamano T AU - Miura K AU - Fukuzawa H MA - fukuzawa@lif.kyoto-u.ac.jp RA - Fukuzawa H TI - Expression analysis of genes associated with the induction of the carbon-concentrating mechanism in Chlamydomonas reinhardtii SO - Plant Physiology. 147(1):340-354, 2008 May. AS - Plant Physiol 2008 May;147(1):340-354 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - E3 ubiquitin ligase MH - Co2 uptake systems MH - Sp strain pcc6803 MH - High light MH - Co2-concentrating mechanism MH - Photosystem-ii MH - Microarray analysis MH - Chloroplast MH - Anhydrase MH - Stress. AB - Acclimation to varying CO2 concentrations and light intensities is associated with the monitoring of environmental changes by controlling genetic and physiological responses through CO2 and light signal transduction. While CO2 and light signals are indispensable for photosynthesis, and these environmental factors have been proposed as strongly associated with each other, studies linking these components are largely limited to work on higher plants. In this study, we examined the physiological characteristics of a green alga, Chlamydomonas reinhardtii, exposed to various light intensities or CO2 concentrations. Acclimation to CO2-limiting conditions by Chlamydomonas requires the induction of a carbon-concentrating mechanism (CCM) to allow the uptake of inorganic carbon (Ci) and increase the affinity for Ci. We revealed that the induction of the CCM is not solely dependent on absolute environmental Ci concentrations but is also affected by light intensity. Using a cDNA array containing 10,368 expressed sequence tags, we also obtained global expression profiles related to the physiological responses. The induction of several CCM-associated genes was strongly affected by high light as well as CO2 concentrations. We identified novel candidates for Ci transporters and CO2-responsive regulatory factors whose expression levels were significantly increased during the induction of the CCM. [References: 77] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Fukuzawa H Kyoto Univ, Grad Sch Biostudies Kyoto 6068502 Japan Kyoto Univ, Grad Sch Biostudies Kyoto 6068502 Japan <16> UI - 2008-308VV-0031 DD - ISI Document Solution: 308VV AU - Busch F AU - Huner NPA AU - Ensminger I MA - ingo.ensminger@ctp.uni-freiburg.de RA - Ensminger I TI - Increased air temperature during simulated autumn conditions impairs photosynthetic electron transport between photosystem II and photosystem I SO - Plant Physiology. 147(1):402-414, 2008 May. AS - Plant Physiol 2008 May;147(1):402-414 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Induced absorbency changes MH - Water-water cycle MH - Chlorophyll fluorescence MH - Cold-acclimation MH - Scots pine MH - Arabidopsis-thaliana MH - Stress responses MH - Terminal oxidase MH - Gene-expression MH - Higher-plants. AB - Changes in temperature and daylength trigger physiological and seasonal developmental processes that enable evergreen trees of the boreal forest to withstand severe winter conditions. Climate change is expected to increase the autumn air temperature in the northern latitudes, while the natural decreasing photoperiod remains unaffected. As shown previously, an increase in autumn air temperature inhibits CO2 assimilation, with a concomitant increased capacity for zeaxanthin-independent dissipation of energy exceeding the photochemical capacity in Pinus banksiana. In this study, we tested our previous model of antenna quenching and tested a limitation in intersystem electron transport in plants exposed to elevated autumn air temperatures. Using a factorial design, we dissected the effects of temperature and photoperiod on the function as well as the stoichiometry of the major components of the photosynthetic electron transport chain in P. banksiana. Natural summer conditions (16-h photoperiod/22 degrees C) and late autumn conditions (8-hphotoperiod/7 degrees C) were compared with a treatment of autumn photoperiod with increased air temperature (SD/HT:8-h photoperiod/22 degrees C) and a treatment with summer photoperiod and autumn temperature (16-h photoperiod/7 degrees C). Exposure to SD/HT resulted in an inhibition of the effective quantum yield associated with a decreased photosystem II/photosystem I stoichiometry coupled with decreased levels of Rubisco. Our data indicate that a greater capacity to keep the primary electron donor of photosystem I (P700) oxidized in plants exposed to SD/HT compared with the summer control may be attributed to a reduced rate of electron transport from the cytochrome b(6)f complex to photosystem I. Photoprotection under increased autumn air temperature conditions appears to be consistent with zeaxanthin-independent antenna quenching through light-harvesting complex II aggregation and a decreased efficiency in energy transfer from the antenna to the photosystem II core. We suggest that models that predict the effect of climate change on the productivity of boreal forests must take into account the interactive effects of photoperiod and elevated temperatures. [References: 68] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Ensminger I Univ Western Ontario, Dept Biol London ON N6A 5B7 Canada Univ Western Ontario, Dept Biol London ON N6A 5B7 Canada Univ Western Ontario, BIOTRON London ON N6A 5B7 Canada Res Ctr, Inst Chem & Dynam Geosphere ICG 2 D-52425 Julich Germany Forest Res Inst Baden Wuerttemberg, Dept Forest Ecol D-79100 Freiburg Germany <17> UI - 2008-308XI-0023 DD - ISI Document Solution: 308XI AU - Jasinski M AU - Sudre D AU - Schansker G AU - Schellenberg M AU - Constant S AU - Martinoia E AU - Bovet L MA - lucien.bovet@pmintl.com RA - Bovet L TI - AtOSA1, a member of the Abc1-like family, as a new factor in cadmium and oxidative stress response SO - Plant Physiology. 147(2):719-731, 2008 Jun. AS - Plant Physiol 2008 Jun;147(2):719-731 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Plant metal tolerance MH - Arabidopsis-thaliana MH - Escherichia-coli MH - Protein-kinase MH - Mitochondrial protein MH - Electron-transfer MH - Bc1 complex MH - Expression MH - Yeast MH - Gene. AB - The analysis of gene expression in Arabidopsis ( Arabidopsis thaliana) using cDNA microarrays and reverse transcription-polymerase chain reaction showed that AtOSA1 ( A. thaliana oxidative stress-related Abc1-like protein) transcript levels are influenced by Cd2+ treatment. The comparison of protein sequences revealed that AtOSA1 belongs to the family of Abc1 proteins. Up to now, Abc1-like proteins have been identified in prokaryotes and in the mitochondria of eukaryotes. AtOSA1 is the first member of this family to be localized in the chloroplasts. However, despite sharing homology to the mitochondrial ABC1 of Saccharomyces cerevisiae, AtOSA1 was not able to complement yeast strains deleted in the endogenous ABC1 gene, thereby suggesting different function between AtOSA1 and the yeast ABC1. The atosa1-1 and atosa1-2 T-DNA insertion mutants were more affected than wild-type plants by Cd2+ and revealed an increased sensitivity toward oxidative stress ( hydrogen peroxide) and high light. The mutants exhibited higher superoxide dismutase activities and differences in the expression of genes involved in the antioxidant pathway. In addition to the conserved Abc1 region in the AtOSA1 protein sequence, putative kinase domains were found. Protein kinase assays in gelo using myelin basic protein as a kinase substrate revealed that chloroplast envelope membrane fractions from the AtOSA1 mutant lacked a 70-kD phosphorylated protein compared to the wild type. Our data suggest that the chloroplast AtOSA1 protein is a new factor playing a role in the balance of oxidative stress. [References: 55] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Bovet L Philip Morris Prod SA, PMI Res & Dev Quai Jeanrenaud 56 CH-2000 Neuchatel Switzerland Univ Zurich, Inst Plant Biol CH-8008 Zurich Switzerland Univ Bern, IPS Plant Nutr CH-3012 Bern Switzerland Univ Geneva, Bioenerget Lab CH-1254 Jussy Lullier Switzerland Univ Fribourg, Dept Biol Plant Biol CH-1700 Fribourg Switzerland Polish Acad Sci, Inst Bioorgan Chem PL-61704 Poznan Poland <18> UI - 2008-308XI-0025 DD - ISI Document Solution: 308XI AU - Nodop A AU - Pietsch D AU - Hocker R AU - Becker A AU - Pistorius EK AU - Forchhammer K AU - Michel KP MA - klauspeter.michel@unibielefeld.de RA - Michel KP TI - Transcript profiling reveals new insights into the acclimation of the mesophilic fresh-water cyanobacterium Synechococcus elongatus PCC 7942 to iron starvation SO - Plant Physiology. 147(2):747-763, 2008 Jun. AS - Plant Physiol 2008 Jun;147(2):747-763 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Synechocystis-sp pcc-6803 MH - Sp strain pcc-6803 MH - Co2 concentrating mechanisms MH - Chlorophyll-binding protein MH - Differential gene-expression MH - Photosystem-i trimers MH - Salt-stressed cells MH - Pcc 6803 MH - Oxidative stress MH - Isiab operon. AB - The regulatory network for acclimation of the obligate photoautotrophic fresh water cyanobacterium Synechococcus elongatus PCC 7942 to iron ( Fe) limitation was studied by transcript profiling with an oligonucleotide whole genome DNA microarray. Six regions on the chromosome with several Fe-regulated genes each were identified. The irpAB and fut region encode putative Fe uptake systems, the suf region participates in [ Fe-sulfur] cluster assembly under oxidative stress and Fe limitation, the isiAB region encodes CP43' and flavodoxin, the idiCB region encodes the NuoE-like electron transport associated protein IdiC and the transcriptional activator IdiB, and the ackA/pgam region encodes an acetate kinase and a phosphoglycerate mutase. We also investigated the response of two S. elongatus PCC 7942 mutants to Fe starvation. These were mutant K10, lacking IdiB but containing IdiC, and mutant MuD, representing a idiC-merodiploid mutant with a strongly reduced amount of IdiC as well as IdiB. The absence of IdiB in mutant K10 or the strongly reduced amount of IdiB in mutant MuD allowed for the identification of additional members of the Fe-responsive IdiB regulon. Besides idiA and the irpAB operon somB( 1), somA( 2), ftr1, ackA, pgam, and nat also seem to be regulated by IdiB. In addition to the reduced amount of IdiB in MuD, the low concentration of IdiC may be responsible for a number of additional changes in the abundance of mainly photosynthesis-related transcripts as compared to the wild type and mutant K10. This fact may explain why it has been impossible to obtain a fully segregated IdiC-free mutant, whereas it was possible to obtain a fully segregated IdiB-free mutant. [References: 95] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Michel KP Univ Bielefeld, Lehrstuhl Mol Zellphysiol D-33615 Bielefeld Germany Univ Bielefeld, Lehrstuhl Mol Zellphysiol D-33615 Bielefeld Germany Univ Bielefeld, Lehrstuhl Genet D-33615 Bielefeld Germany Univ Tubingen, Lehrstuhl Mikrobiol & Organism Interakt D-72076 Tubingen Germany <19> UI - 2008-308XI-0026 DD - ISI Document Solution: 308XI AU - Matringe M AU - Ksas B AU - Rey P AU - Havaux M MA - michel.havaux@cea.fr RA - Havaux M TI - Tocotrienols, the unsaturated forms of vitamin E, can function as antioxidants and lipid protectors in tobacco leaves SO - Plant Physiology. 147(2):764-778, 2008 Jun. AS - Plant Physiol 2008 Jun;147(2):764-778 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Chilling-enhanced photooxidation MH - Sulfoxide reductase-a MH - Alpha-tocopherol MH - Arabidopsis-thaliana MH - Oxidative stress MH - Spinach-chloroplasts MH - Photon-emission MH - Transgenic tobacco MH - Gamma-tocopherol MH - Low-temperatures. AB - Vitamin E is a generic term for a group of lipid-soluble antioxidant compounds, the tocopherols and tocotrienols. While tocotrienols are considered as important vitamin E components in humans, with functions in health and disease, the protective functions of tocotrienols have never been investigated in plants, contrary to tocopherols. We took advantage of the strong accumulation of tocotrienols in leaves of double transgenic tobacco ( Nicotiana tabacum) plants that coexpressed the yeast ( Saccharomyces cerevisiae) prephenate dehydrogenase gene ( PDH) and the Arabidopsis ( Arabidopsis thaliana) hydroxyphenylpyruvate dioxygenase gene ( HPPD) to study the antioxidant function of those compounds in vivo. In young leaves of wild-type and transgenic tobacco plants, the majority of vitamin E was stored in thylakoid membranes, while plastoglobules contained mainly delta-tocopherol, a very minor component of vitamin E in tobacco. However, the vitamin E composition of plastoglobules was observed to change substantially during leaf aging, with alpha-tocopherol becoming the major form. Tocotrienol accumulation in young transgenic HPPD-PDH leaves occurred without any significant perturbation of photosynthetic electron transport. Tocotrienols noticeably reinforced the tolerance of HPPD-PDH leaves to high light stress at chilling temperature, with photosystem II photoinhibition and lipid peroxidation being maintained at low levels relative to wild-type leaves. Very young leaves of wild-type tobacco plants turned yellow during chilling stress, because of the strongly reduced levels of chlorophylls and carotenoids, and this phenomenon was attenuated in transgenic HPPD-PDH plants. While sugars accumulated similarly in young wild-type and HPPD-PDH leaves exposed to chilling stress in high light, a substantial decrease in tocotrienols was observed in the transgenic leaves only, suggesting vitamin E consumption during oxygen radical scavenging. Our results demonstrate that tocotrienols can function in vivo as efficient antioxidants protecting membrane lipids from peroxidation. [References: 91] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Havaux M CEA, Direct Sci Vivant, Inst Biol Environm & Biotechnol, Lab Ecophysiol Mol Plantes F-13108 St Paul Les Durance France CEA, Direct Sci Vivant, Inst Biol Environm & Biotechnol, Lab Ecophysiol Mol Plantes F-13108 St Paul Les Durance France CEA, Inst Rech Technol & Sci Vivant, Physiol Cellulaire Vegetale Lab F-38054 Grenoble 9 France CNRS, UMR Biol Vegetale & Microbiol Environm F-13108 St Paul Les Durance France Univ Aix Marseille F-13108 St Paul Les Durance France <20> UI - 2008-308XI-0033 DD - ISI Document Solution: 308XI AU - Carr H AU - Axelsson L MA - carr@botan.su.se RA - Carr H TI - Photosynthetic utilization of bicarbonate in Zostera marina is reduced by inhibitors of mitochondrial ATPase and electron transport SO - Plant Physiology. 147(2):879-885, 2008 Jun. AS - Plant Physiol 2008 Jun;147(2):879-885 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Inorganic carbon acquisition MH - Co2 concentrating mechanisms MH - Barley hordeum-vulgare MH - Mesophyll protoplasts MH - Oxidative-metabolism MH - Laminaria-saccharina MH - Uncoupling protein MH - Plasma-membrane MH - Chara-corallina MH - Zmpump encodes. AB - When Zostera marina was irradiated after a period of darkness, initiation of photosynthetic O-2 evolution occurred in two phases. During a lag phase, lasting 4 to 5 min, photosynthesis was supported by a diffusive entry of CO2. Photosynthesis then rapidly increased to its full rate. Tris buffer, at a concentration of 50 mM, completely inhibited this increase without affecting CO2- supported photosynthesis during the lag phase. These results verify that the increase in photosynthesis after the lag phase depended on an activation of bicarbonate (HCO3-) utilization through acid zones generated by proton pumps located to the outer cell membrane. In similar experiments, 6.25 mu M of the mitochondrial ATPase blocker oligomycin inhibited photosynthetic HCO3- utilization by more than 60%. Antimycin A, a selective blocker of mitochondrial electron transport, caused a similar inhibition of HCO3- utilization. Measurements at elevated CO2 concentrations verified that neither oligomycin nor antimycin interfered with linear photosynthetic electron transport or with CO2 fixation. Thus, a major part of the ATP used for the generation of acid zones involved in HCO3- utilization in Z. marina was derived from mitochondrial respiration. [References: 52] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Carr H Stockholm Univ, Dept Bot SE-10691 Stockholm Sweden Stockholm Univ, Dept Bot SE-10691 Stockholm Sweden Kristineberg Marine Res Stn SE-45034 Fiskenbaeckskil Sweden <21> UI - 2008-308UM-0013 DD - ISI Document Solution: 308UM AU - Phillips MA AU - D'Auria JC AU - Gershenzon J AU - Pichersky E MA - mapgmy@ibmb.csic.es, dauria@ice.mpg.de, gershenzon@ice.mpg.de RA - Gershenzon J TI - The Arabidopsis thaliana type I isopentenyl diphosphate isomerases are targeted to multiple subcellular compartments and have overlapping functions in isoprenoid biosynthesis SO - Plant Cell. 20(3):677-696, 2008 Mar. AS - Plant Cell 2008 Mar;20(3):677-696 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 1040-4651 MH - Methylerythritol phosphate-pathway MH - Non-mevalonate pathway MH - Escherichia-coli MH - Dimethylallyl diphosphate MH - Saccharomyces-cerevisiae MH - Independent biosynthesis MH - Ubiquinone biosynthesis MH - Pyrophosphate isomerase MH - Terpenoid volatiles MH - Plastidial pathways. AB - To form the building blocks of isoprenoids, isopentenyl diphosphate (IPP) isomerase activity, which converts IPP to dimethylallyl diphosphate (DMAPP), appears to be necessary in cytosol, plastids, and mitochondria. Arabidopsis thaliana contains only two IPP isomerases (Isopentenyl Diphosphate Isomerase1 [IDI1] and IDI2). Both encode proteins with N-terminal extensions similar to transit peptides and are expressed in all organs, with IDI1 less abundant than IDI2. Examination of enhanced green fluorescent protein fusions established that IDI1 is mainly in the plastid, whereas IDI2 is mainly in the mitochondria. Both proteins are also in the cytosol as a result of their translation from naturally occurring shorter transcripts lacking transit peptides, as demonstrated by 5' rapid amplification of cDNA ends cloning. IPP isomerase activity in the cytosol was confirmed by uniform labeling of IPP- and DMAPP-derived units of the cytoplasmic isoprenoid product, sitosterol, when labeled mevalonate was administered. Analysis of mutant lines showed that double mutants were nonviable, while homozygous single mutants had no major morphological or chemical differences from the wild type except for flowers with fused sepals and underdeveloped petals on idi2 mutants. Thus, each of the two Arabidopsis IPP isomerases is found in multiple but partially overlapping subcellular locations, and each can compensate for the loss of the other through partial redundancy in the cytosol. [References: 67] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Gershenzon J Max Planck Inst Chem Ecol D-07745 Jena Germany Max Planck Inst Chem Ecol D-07745 Jena Germany Univ Michigan, Dept Mol Cellular & Dev Biol Ann Arbor, MI 48109 USA <22> UI - 2008-308UT-0012 DD - ISI Document Solution: 308UT AU - de Bianchi S AU - Dall'Osto L AU - Tognon G AU - Morosinotto T AU - Bassi R MA - bassi@sci.univr.it RA - Bassi R TI - Minor antenna proteins CP24 and CP26 affect the interactions between photosystem II Subunits and the electron transport rate in grana membranes of Arabidopsis SO - Plant Cell. 20(4):1012-1028, 2008 Apr. AS - Plant Cell 2008 Apr;20(4):1012-1028 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 1040-4651 MH - Light-harvesting complex MH - Chlorophyll-a/b-proteins MH - Barley plastid membranes MH - Chlamydomonas-reinhardtii MH - Thylakoid membrane MH - Energy-dissipation MH - Supramolecular organization MH - Photosynthetic apparatus MH - Plant chloroplasts MH - Xanthophyll cycle. AB - We investigated the function of chlorophyll a/b binding antenna proteins Chlorophyll Protein 26 (CP26) and CP24 in light harvesting and regulation of photosynthesis by isolating Arabidopsis thaliana knockout lines that completely lacked one or both of these proteins. All three mutant lines had a decreased efficiency of energy transfer from trimeric light-harvesting complex II (LHCII) to the reaction center of photosystem II (PSII) due to the physical disconnection of LHCII from PSII and formation of PSII reaction center depleted domains in grana partitions. Photosynthesis was affected in plants lacking CP24 but not in plants lacking CP26: the former mutant had decreased electron transport rates, a lower Delta pH gradient across the grana membranes, reduced capacity for nonphotochemical quenching, and limited growth. Furthermore, the PSII particles of these plants were organized in unusual two-dimensional arrays in the grana membranes. Surprisingly, overall electron transport, nonphotochemical quenching, and growth of the double mutant were restored to wild type. Fluorescence induction kinetics and electron transport measurements at selected steps of the photosynthetic chain suggested that limitation in electron transport was due to restricted electron transport between Q(A) and Q(B), which retards plastoquinone diffusion. We conclude that CP24 absence alters PSII organization and consequently limits plastoquinone diffusion. [References: 78] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Bassi R Univ Verona, Dipartimento Sci Tecnol I-37134 Verona Italy Univ Verona, Dipartimento Sci Tecnol I-37134 Verona Italy Univ Padua, Dipartimento Biol I-35131 Padua Italy <23> UI - 2008-308UT-0013 DD - ISI Document Solution: 308UT AU - Chuartzman SG AU - Nevo R AU - Shimoni E AU - Charuvi D AU - Kiss V AU - Ohad I AU - Brumfeld V AU - Reich Z MA - vlad.brumfeld@weizmann.ac.il, ziv.reich@weizmann.ac.il RA - Brumfeld V TI - Thylakoid membrane remodeling during state transitions in Arabidopsis SO - Plant Cell. 20(4):1029-1039, 2008 Apr. AS - Plant Cell 2008 Apr;20(4):1029-1039 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 1040-4651 MH - Light-harvesting-complex MH - Protein-phosphorylation MH - Photosystem-ii MH - Chloroplast membranes MH - Chlorophyll fluorescence MH - Pea-chloroplasts MH - In-vivo MH - Organization MH - Stacking MH - Plants. AB - Adaptability of oxygenic photosynthetic organisms to fluctuations in light spectral composition and intensity is conferred by state transitions, short-term regulatory processes that enable the photosynthetic apparatus to rapidly adjust to variations in light quality. In green algae and higher plants, these processes are accompanied by reversible structural rearrangements in the thylakoid membranes. We studied these structural changes in the thylakoid membranes of Arabidopsis thaliana chloroplasts using atomic force microscopy, scanning and transmission electron microscopy, and confocal imaging. Based on our results and on the recently determined three-dimensional structure of higher-plant thylakoids trapped in one of the two major light-adapted states, we propose a model for the transitions in membrane architecture. The model suggests that reorganization of the membranes involves fission and fusion events that occur at the interface between the appressed (granal) and nonappressed (stroma lamellar) domains of the thylakoid membranes. Vertical and lateral displacements of the grana layers presumably follow these localized events, eventually leading to macroscopic rearrangements of the entire membrane network. [References: 58] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Brumfeld V Weizmann Inst Sci, Dept Plant Sci IL-76100 Rehovot Israel Weizmann Inst Sci, Dept Plant Sci IL-76100 Rehovot Israel Weizmann Inst Sci, Dept Biol Chem IL-76100 Rehovot Israel Weizmann Inst Sci, Electron Microscopy Unit IL-76100 Rehovot Israel Hebrew Univ Jerusalem, Robert H Smith Inst Plant Sci & Genet Agr IL-76100 Rehovot Israel Hebrew Univ Jerusalem, Inst Life Sci IL-91014 Jerusalem Israel Hebrew Univ Jerusalem, Avron Even Ari Minerva Ctr Photosynth Res IL-91014 Jerusalem Israel <24> UI - 2008-307TF-0001 DD - ISI Document Solution: 307TF AU - Bartak M AU - Vrablikova-Cempirkova H AU - Stepigova J AU - Hajek J AU - Vaczi P AU - Vecerova K MA - cempirkova@sci.muni.cz RA - Vrablikova-Cempirkova H TI - Duration of irradiation rather than quantity and frequency of high irradiance inhibits photosynthetic processes in the lichen Lasallia pustulata SO - Photosynthetica. 46(2):161-169, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):161-169 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Chlorophyll fluorescence MH - Non-photochemical quenching MH - Photoinhibition MH - Photochemical quenching MH - Xanthophyll cycle MH - Zeaxanthin. MH - Chlorophyll-a fluorescence MH - Xanthophyll cycle MH - Photosystem-ii MH - Lobaria-pulmonaria MH - High-light MH - Xanthoria-parietina MH - Seasonal-changes MH - Physiological interpretation MH - Umbilicaria-antarctica MH - Carotenoid composition. AB - Lichen thalli were exposed to 4 regimes differing in irradiance and duration of irradiation. Photosynthetic efficiency of thalli was monitored by chlorophyll fluorescence parameters and xanthophyll cycle analysis. Maximal quantum yield of photosystem 2 (F-V/F-M) decreased gradually with time in long-term treatment. The effect of additional short-term high irradiance (HI) treatment applied each 24 h was not significant. Nevertheless, short-term HI applied repeatedly on thalli kept in the dark led to a significant decrease of F-V/F-M. Non-photochemical quenching recorded during the long-term treatment corresponded to the content of zeaxanthin (Z). In short-term treatment, however, proportion of Z (and antheraxanthin) to total amount of xanthophyll cycle pigments recovered to the initial values every 24 h after each repeated short-term HI event in thalli kept in dark. Thus duration of irradiation rather than irradiance and frequency of HI events is important for a decrease in primary photosynthetic processes in wet thalli of Lasallia pustulata. Rapidly responding photoprotective mechanisms, such as conversion of xanthophyll cycle pigments, are involved mainly in short-term irradiation events, even at HI. [References: 50] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Vrablikova-Cempirkova H Masaryk Univ, Inst Expt Biol, Dept Plant Physiol & Anat Kotlarska 2 CS-61137 Brno Czech Republic Masaryk Univ, Inst Expt Biol, Dept Plant Physiol & Anat CS-61137 Brno Czech Republic <25> UI - 2008-307TF-0002 DD - ISI Document Solution: 307TF AU - Kornyeyev D AU - Holaday AS MA - kornyeyev@yahoo.com RA - Kornyeyev D TI - Corrections to current approaches used to calculate energy partitioning in photosystem 2 SO - Photosynthetica. 46(2):170-178, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):170-178 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Arabidopsis MH - Chlorophyll fluorescence MH - Gossypium MH - Lincomycin MH - Lycopersicon MH - Mutant MH - Psbs protein MH - Thermal dissipation. MH - Photosynthetic electron-transport MH - Absorbed light energy MH - Chlorophyll fluorescence MH - Barley leaves MH - Photoinactivation MH - Excitation MH - Dissipation MH - Parameters MH - Plants MH - Photoinhibition. AB - We analyzed several approaches dealing with the components of non-photochemical energy dissipation and introduced improved versions of the equations used to calculate this parameter. The usage of these formulae depends on the conditions of the sample (acclimation to dark or irradiation, presence or absence of the "actinic light"). The parameter known as "excess" cannot be used as a component of energy partitioning. In reality, this parameter reflects the differences between potential and actual quantum yields of photochemistry. [References: 34] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Kornyeyev D Univ Calif Merced, Sch Engn N Lake Rd Merced, CA 95343 USA Texas Tech Univ, Dept Biol Sci Lubbock, TX 79409 USA Ukrainian Acad Sci, Inst Plant Physiol & Genet UA-03022 Kiev Ukraine <26> UI - 2008-307TF-0004 DD - ISI Document Solution: 307TF AU - Liu XY AU - Li B AU - Yang JH AU - Sui N AU - Yang XM AU - Meng QW MA - qwmeng@sdau.edu.cn RA - Meng QW TI - Overexpression of tomato chloroplast omega-3 fatty acid desaturase gene alleviates the photoinhibition of photosystems 2 and 1 under chilling stress SO - Photosynthetica. 46(2):185-192, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):185-192 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Chlorophyll fluorescence induction MH - Linolenic acids (18 : 3) MH - Lycopersicon esculentum MH - Northern blot MH - Oxygen evolution MH - Photoinhibition. MH - Antisense-mediated depletion MH - Fatty-acid-composition MH - Membrane-lipids MH - Sulfoquinovosyl diacylglycerol MH - Photosynthetic machinery MH - Energy-dissipation MH - Growth temperature MH - Freezing tolerance MH - Cold-acclimation MH - Low irradiance. AB - In transgenic (TG) tomato (Lycopersicon esculentum Mill.) overexpressed omega-3 fatty acid desaturase gene (LeFAD7) was identified, which was controlled by the cauliflower mosaic virus 35S promoter and induced increased contents of unsaturated fatty acids in thylakoid membrane. Under chilling stress at low irradiance (4 degrees C, 100 mu mol m(-2)s(-1)) TG plants with higher linolenic acids (18: 3) content maintained a higher O-2 evolution rate, oxidizable P700 content, and maximal photochemical efficiency (F-v/F-m) than wild type (WT) plants. Low temperature treatment for 6 h resulted in extensive changes of chloroplast ultrastructure: in WT plants most chloroplasts became circular, the number of amyloids increased, appressed granum stacks were dissolved, grana disappeared, and the number of grana decreased, while only a few grana were found in leaves of TG plants. Hence the overexpression of LeFAD7 could increase the content of 18: 3 in thylakoid membrane, and this increase alleviated the photoinhibition of photosystem (PS) 1 and PS2 under chilling at low irradiance. [References: 62] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Meng QW Shandong Agr Univ, Coll Life Sci, State Key Lab Crop Biol Tai An 271018 Shandong Peoples R China Shandong Agr Univ, Coll Life Sci, State Key Lab Crop Biol Tai An 271018 Shandong Peoples R China Zhejiang Univ, Sch Med Hangzhou 310058 Zhejiang Peoples R China Zhejiang Univ, Dept Hort Hangzhou 310029 Zhejiang Peoples R China <27> UI - 2008-307TF-0005 DD - ISI Document Solution: 307TF AU - Guan QZ AU - Guo YH AU - Sui XL AU - Li W AU - Zhang ZX MA - Zhangzx@cau.edu.cn RA - Zhang ZX TI - Changes in photosynthetic capacity and antioxidant enzymatic systems in micropropagated Zingiber officinale plantlets during their acclimation SO - Photosynthetica. 46(2):193-201, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):193-201 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Antioxidative enzymes MH - Chlorophyll content and fluorescence MH - Chloroplast ultrastructure MH - Ginger MH - Dry mass MH - Net photosynthetic rate MH - Photochemical quenching MH - Plant height. MH - Ex-vitro acclimatization MH - In-vitro MH - Chlorophyll fluorescence MH - Carbon metabolism MH - Growth MH - Regeneration MH - Cultures MH - Calathea MH - Invitro MH - Ginger. AB - Ginger (Zingiber officinale Rosc.) plantlets were propagated in vitro and acclimated under different photosynthetic photon flux densities (60 and 250 mu mol m(-2) s(-1) = LI and HI, respectively). Increases in chlorophyll (Chl) content and Chl a/b ratio were found under both irradiances. In vitro plantlets (day 0) exhibited a low photosynthesis, but chloroplasts from in vitro leaves contained well developed grana and osmiophillic globules. Photoinhibition in leaves formed in vitro was characterized by decrease of photochemical efficiency and quantum efficiency of photosystem 2 photochemistry in HI treatment during acclimation. The new leaves formed during acclimation in both treatments showed a higher photosynthetic capacity than the leaves formed in vitro. Also activities of antioxidant enzymes of micropropagated ginger plantlets changed during acclimation. [References: 37] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Zhang ZX China Agr Univ, Coll Agron & Biotechnol Beijing 100094 Peoples R China China Agr Univ, Coll Agron & Biotechnol Beijing 100094 Peoples R China <28> UI - 2008-307TF-0006 DD - ISI Document Solution: 307TF AU - Sobrado MA MA - msobrado@usb.ve RA - Sobrado MA TI - Leaf characteristics and diurnal variation of chlorophyll fluorescence in leaves of the 'Bana' vegetation of the Amazon region SO - Photosynthetica. 46(2):202-207, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):202-207 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Acclimation MH - Down regulation MH - Leaf c/n MH - Nitrogen deficiency MH - Photo-protection MH - Sclerophyllous leaves MH - Species differences MH - Delta c-13 MH - Delta n-15. MH - Photosynthetic activity MH - Young leaves MH - Rain-forests MH - Photoinhibition MH - Nitrogen MH - Parameters MH - Light MH - Ratio MH - Photosystem-2 MH - Temperature. AB - In six dominant species of the Amazonian 'Bana' vegetation, leaf blade characteristics, pigment composition, and chlorophyll (Chl) fluorescence parameters were measured in young and mature leaves under field conditions. Leaf delta C-13 was comparable in the six species, which suggested that both expanding and expanded leaves contained organic matter fixed under similar intercellular and ambient CO2 concentration (C-i/C-a). High leaf C/N and negative delta N-15 values found in this habitat were consistent with the extreme soil N-deficiency. Analysis of Chl and carotenoids showed that expanding leaves had an incomplete development of photosynthetic antenna when compared to adult leaves. Dynamic inactivation of photosystem 2 (PS2) at midday was observed at both leaf ages as F-v/F-m decreased compared to predawn values. Adult leaves reached overnight F-v/F-m ratios typical of healthy leaves. Overnight recovery of F-v/F-m in expanding leaves was incomplete. F-0 remained unchanged from midday to predawn and F-v tended to increase from midday to predawn. The recovery from midday depression observed in adult leaves suggested an acclimatory down-regulation associated with photo-protection and non-damage of PS2. [References: 38] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Sobrado MA Univ Simon Bolivar, Dept Biol Organismos, Lab Biol Ambiental Plantas Apartado 89-000 Caracas 1080A Venezuela Univ Simon Bolivar, Dept Biol Organismos, Lab Biol Ambiental Plantas Caracas 1080A Venezuela <29> UI - 2008-307TF-0007 DD - ISI Document Solution: 307TF AU - Georgieva K AU - Lenk S AU - Buschmann C MA - katya@bio21.bas.bg RA - Georgieva K TI - Responses of the resurrection plant Haberlea rhodopensis to high irradiance SO - Photosynthetica. 46(2):208-215, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):208-215 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Carotenoids MH - Chlorophyll fluorescence MH - Desiccation tolerant plant MH - Drought stress MH - Fluorescence imaging MH - Leaf area MH - Net photosynthetic rate MH - Transpiration rate MH - Water use efficiency. MH - Desiccation-tolerant plants MH - Blue-green fluorescence MH - Chlorophyll fluorescence MH - Photosynthetic activity MH - Carbon assimilation MH - Water deficits MH - Leaves MH - Light MH - Rehydration MH - Protection. AB - The effect of high irradiance (HI) during desiccation and subsequent rehydration of the homoiochlorophyllous desiccation-tolerant shade plant Haberlea rhodopensis was investigated. Plants were irradiated with a high quantum fluence rate (HI; 350 mu mol m(-2) s(-1) compared to ca. 30 mu mol m(-2) s(-1) at the natural rock habitat below trees) and subjected either to fast desiccation (tufts dehydrated with naturally occurring thin soil layers) or slow desiccation (tufts planted in pots in peat-soil dehydrated by withholding irrigation). Leaf water content was 5 % of the control after 4 d of fast and 19 d of slow desiccation. Haberlea was very sensitive to HI under all conditions. After 19 d at HI, even in well-watered plants there was a strong reduction of rates of net photosynthesis and transpiration, contents of chlorophyll (Chl) and carotenoids, as well as photosystem 2 activity (detected by the Chl fluorescence ratio R-Fd). Simultaneously, the blue/red and green/red fluorescence ratios increased considerably suggesting increased synthesis of polyphenolic compounds. Desiccation of plants in HI induced irreversible changes in the photosynthetic apparatus and leaves did not recover after rehydration regardless of fast or slow desiccation. Only young leaves survived desiccation. [References: 29] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Georgieva K Bulgarian Acad Sci, Inst Plant Physiol Acad G Bonchev Str,Bl 21 BG-1113 Sofia Bulgaria Bulgarian Acad Sci, Inst Plant Physiol BG-1113 Sofia Bulgaria Univ Karlsruhe, Botan Inst Mol Biol & Biochim Pflanzen 2 D-76128 Karlsruhe Germany <30> UI - 2008-307TF-0008 DD - ISI Document Solution: 307TF AU - Baligar VC AU - Bunce JA AU - Machado RCR AU - Elson MK MA - VC.Baligar@ars.usda.gov RA - Baligar VC TI - Photosynthetic photon flux density, carbon dioxide concentration, and vapor pressure deficit effects on photosynthesis in cacao seedlings SO - Photosynthetica. 46(2):216-221, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):216-221 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Leaf internal co2 concentration MH - Net photosynthesis MH - Stomatal conductance MH - Theobroma cacao MH - Transpiration rate. MH - Long-term exposure MH - Theobroma-cacao MH - Chlorophyll fluorescence MH - Co2 concentration MH - Irradiance level MH - Gas-exchange MH - Responses MH - Growth MH - Humidity MH - Conductance. AB - Independent short-term effects of photosynthetic photon flux density (PPFD) of 50-400 mu mol m(-2) s(-1), external CO2 concentration (C-a) of 85-850 cm(3) m(-3), and vapor pressure deficit (VPD) of 0.9-2.2 kPa on net photosynthetic rate (P-N), stomatal conductance (g(s)), leaf internal CO2 concentration (C-i), and transpiration rates (E) were investigated in three cacao genotypes. In all these genotypes, increasing PPFD from 50 to 400 mu mol m(-2) s(-1) increased P-N by about 50 %, but further increases in PPFD up to 1 500 mu mol m(-2) s(-1) had no effect on P-N. Increasing C-a significantly increased P-N and C-i while g(s) and E decreased more strongly than in most trees that have been studied. In all genotypes, increasing VPD reduced P-N, but the slight decrease in g(s) and the slight increase in C-i with increasing VPD were non-significant. Increasing VPD significantly increased E and this may have caused the reduction in P-N. The unusually small response of g(s) to VPD could limit the ability of cacao to grow where VPD is high. There were no significant differences in gas exchange characteristics (g(s), C-i, E) among the three cacao genotypes under any measurement conditions. [References: 43] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Baligar VC USDA ARS, Sustainable Perennial Crops Lab Beltsville, MD USA USDA ARS, Sustainable Perennial Crops Lab Beltsville, MD USA USDA ARS, Crop Syst & Global Change Lab Beltsville, MD USA Mars Ctr Cacao Sci Itajuipe BA Brazil <31> UI - 2008-307TF-0009 DD - ISI Document Solution: 307TF AU - Ramirez DA AU - Valladares F AU - Domingo F AU - Bellot J MA - DavidAntonio.Ramirez@uclm.es RA - Ramirez DA TI - Seasonal water-use efficiency and chlorophyll fluorescence response in alpha grass (Stipa tenacissima L.) is affected by tussock size SO - Photosynthetica. 46(2):222-231, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):222-231 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Leaf area index MH - Net photosynthetic rate MH - Photoinhibition MH - Photosystem 2 MH - Plant size MH - Semiaridity MH - Stomatal conductance MH - Transpiration rate MH - Water stress. MH - Plant size MH - Semiarid environment MH - Stomatal conductance MH - Photosynthetic rate MH - Crown architecture MH - Gas-exchange MH - Leaf MH - Soil MH - Transpiration MH - Physiology. AB - Twelve randomly chosen Stipa tenacissima L. individuals were grouped into three tussock size classes, small (ST), medium (MT), and large (LT) with 5.6 +/- 0.8, 34.1 +/- 4.2, and 631.9 +/- 85.8 g of dry green foliar matter, respectively, in three plots with different S. tenacissima cover. Instantaneous (WUEi) and long-term (WUEl) water-use efficiencies were measured in two seasons of contrasting volumetric soil water content (early winter 21.0 +/- 0.8 % and summer 5.8 +/- 0.3 %). Maximum photochemical efficiency of photosystem 2 and stomatal conductance in summer assessed the extent of water and irradiance stress in tussocks of different size. WUEi was lower in MT and ST "water spender" strategies than in LT during the high water-availability season. In summer net photosynthetic rate and WUEi were higher and photoinhibition was lower in LT than in MT and ST. Significant spatial variability was found in WUEi. Water uptake was competitive in stands with denser alpha grass and more water availability in summer, reducing their WUEi. However, WUEl showed a rising tendency when water became scarce. Thus it is important to explicitly account for plant size in ecophysiological studies, which must be combined with demographic information when estimating functional processes at stand level in sequential scaling procedures. [References: 47] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Ramirez DA Univ Castilla La Mancha, Dept Ciencias Ambientales Ap 45071 Toledo Spain Univ Castilla La Mancha, Dept Ciencias Ambientales Toledo Spain Univ Alicante, Dept Ecol E-03080 Alicante Spain Univ Almeria, Escuela Politecn Super, Dept Biol Vegetal & Ecol Almeria 04120 Spain CSIC, Estac Expt Zonas Aridas Almeria 04001 Spain CSIC, Inst Recursos Nat, Ctr Ciencias Medioambientales E-28006 Madrid Spain Univ Rey Juan Carlos, Escuela Super Ciencias Expt & Tecnol, Dept Biol & Geol Mostoles 28933 Spain <32> UI - 2008-307TF-0010 DD - ISI Document Solution: 307TF AU - Bai J AU - Xu DH AU - Kang HM AU - Chen K AU - Wang G MA - baijuan03@lzu.cn, wgmg36@lzu.edu.cn RA - Wang G TI - Photoprotective function of photorespiration in Reaumuria soongorica during different levels of drought stress in natural high irradiance SO - Photosynthetica. 46(2):232-237, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):232-237 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Chlorophyll fluorescence MH - Electron flow MH - Gas exchange MH - Hydrogen peroxide MH - Intercellular co2 concentration MH - Isonicotinic acid hydrazide MH - Leaf abscission MH - Leaf temperature MH - Photoinhibition MH - Stomatal conductance. MH - Photosynthetic electron flow MH - Photosystem-ii activity MH - Net co2 assimilation MH - Water-stress MH - Mediterranean plants MH - C-3 plants MH - In-vivo MH - Leaves MH - Photoinhibition MH - Oxygen. AB - Diurnal patterns of gas exchange and chlorophyll (Chl) fluorescence parameters of photosystem 2 (PS2) as well as H2O2 content were analyzed in Reaumuria soongorica (Pall.) Maxim., a perennial semi-shrub. The rate of photorespiration was estimated by combined measurement of gas exchange and Chl fluorescence. The rate of photorespiration increased with the increasing drought stress (DS). The ratio of carboxylation electron flow to oxygenation electron flow (J(c)/J(o)) and the maximal photochemical efficiency of PS2 (variable to maximum fluorescence ratio, F-v/F-m) decreased with the increasing DS. F-v/F-m in isonicotinic acid hydrazide (INH)-sprayed plants was lower than that in normal plants under moderate DS, but no significant difference was observed under severe DS. H2O2 content in INH-sprayed plants was significantly lower than that in normal plants under severe DS. Taken together, photorespiration in R. soongorica consumed excess electrons and protected photosynthetic apparatus under moderate DS, whereas it accelerated H2O2 accumulation markedly and induced the leaf abscission under severe DS. [References: 35] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Wang G Lanzhou Univ, Key Lab Arid & Grassland Ecol, Minist Educ Lanzhou 730000 Peoples R China Lanzhou Univ, Key Lab Arid & Grassland Ecol, Minist Educ Lanzhou 730000 Peoples R China <33> UI - 2008-307TF-0014 DD - ISI Document Solution: 307TF AU - Yiotis C AU - Psaras GK AU - Manetas Y MA - chyiotis@upatras.gr RA - Yiotis C TI - Seasonal photosynthetic changes in the green-stemmed Mediterranean shrub Calicotome villosa: a comparison with leaves SO - Photosynthetica. 46(2):262-267, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):262-267 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Carotenoids MH - Chlorophyll MH - Drought stress MH - Electron transport rates MH - Photoinhibition MH - Photosystem 2 efficiency MH - Spiny broom. MH - Phlomis-fruticosa l MH - Warm desert shrub MH - Field conditions MH - Photochemical efficiency MH - Gas-exchange MH - Chlorophyll fluorescence MH - Water relations MH - Sonoran desert MH - Drought MH - Patterns. AB - Some photosynthetic attributes of leaves and stems were seasonally followed in the small-leaved, summer-deciduous, green-stemmed Mediterranean shrub Calicotome villosa. Both leaves and stems displayed similar photon energy-saturated photosystem 2 (PS2) efficiencies with a minimum during winter. A second minimum in stems during the leafless summer period could be ascribed to sustained photoinhibition. Yet, stems were slightly inferior in photon capture, resulting partly from lower chlorophyll (Chl) contents and partly from higher reflectance due to pubescence. As a result, photon energy-saturated linear electron transport rates were slightly higher in leaves. However, when the total leaf and stem areas were taken into account, this superiority was abolished during autumn and winter and more than overturned during spring. Given that during summer the stems were the only photosynthetic organs, the yearly photosynthetic contribution of stems was much higher. Chl contents in stems displayed a transient and considerable summer drop, accompanied by an increase in the carotenoid to Chl ratio, indicating a photo-protective adaptation to summer drought through a decrease of photo-selective capacity, typical for leaves of many Mediterranean plants. [References: 36] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Yiotis C Univ Patras, Dept Biol, Sect Plant Biol GR-26500 Patras Greece Univ Patras, Dept Biol, Sect Plant Biol GR-26500 Patras Greece <34> UI - 2008-307TF-0015 DD - ISI Document Solution: 307TF AU - Bacso R AU - Molnar A AU - Papp I AU - Janda T MA - istvan@uni-corvinus.hu RA - Papp I TI - Photosynthetic behaviour of Arabidopsis plants with a Cap Binding Protein 20 mutation under water stress SO - Photosynthetica. 46(2):268-272, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):268-272 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Drought MH - Fluorescence induction MH - Thermoluminescence MH - Water potential. MH - Chlorophyll fluorescence MH - Lipid-peroxidation MH - Thermoluminescence afterglow MH - Drought stress MH - Leaves MH - Metabolism MH - Growth MH - Inhibition MH - Parameters MH - Tolerance. AB - Under non-stressed conditions the net photosynthetic rate (P-N) of the mutant plants cbp20 of Arabidopsis was similar to that of the wild type (WT). In response to water deprivation, however, P-N started to decrease later in the mutants and remained substantially higher. Thermoluminescence measurements showed that the lipid peroxidation induced by severe water stress was also less pronounced in the mutant than in the WT. Both soil gravimetric and plant water potential data showed that cbp20 mutants lose water more slowly than the WT plants. The drought-induced decline in F-v/F-m, the quantum efficiency of photosystem 2, and photochemical quenching parameters also started later in the cbp20 mutants than in the WT plants. Thus the restricted gas exchange in the cbp20 mutants does not impair the photosynthetic performance of the plant; however, under drought improved water retention provides significant protection for the photosynthetic apparatus. [References: 36] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Papp I Corvinus Univ Budapest, Dept Plant Physiol & Plant Biochem POB 53 H-1518 Budapest Hungary Corvinus Univ Budapest, Dept Plant Physiol & Plant Biochem H-1518 Budapest Hungary Hungarian Acad Sci, Agr Res Inst H-2462 Martonvasar Hungary <35> UI - 2008-307TF-0019 DD - ISI Document Solution: 307TF AU - Stepigova J AU - Gauslaa Y AU - Cempirkova-Vrablikova H AU - Solhaug KA MA - knut.solhaug@umb.no RA - Solhaug KA TI - Irradiance prior to and during desiccation improves the tolerance to excess irradiance in the desiccated state of the old forest lichen Lobaria pulmonaria SO - Photosynthetica. 46(2):286-290, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):286-290 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Chlorophyll fluorescence MH - Photosynthetic quenching MH - Photoinhibition MH - Xanthophyll cycle. MH - Xanthoria-parietina MH - Xanthophyll cycle MH - Physiological interpretation MH - Photosynthetic productivity MH - Chlorophyll fluorescence MH - Lecanora-muralis MH - Co2 exchange MH - Umbilicaria-antarctica MH - Net photosynthesis MH - Drive acclimation. AB - Hydrated thalli of the lichen Lobaria pulmonaria were either preconditioned to dim irradiance (DI, 5 mu mol m(-2) s(-1)) or medium irradiance (MI, 200 mu mol m(-2) s(-1)) for 6 h. After this 6 h period, the thalli were allowed to desiccate under the two respective irradiances. Thereafter, these dry lichens were exposed to high irradiance (HI, 1 000 mu mol m(-2) s(-1)) for 60 h. After this HI treatment, the maximal photochemical quantum yield (F-V/F-M) and the de-epoxidation state of xanthophyll cycle pigments (DEPS) were highest in thalli preconditioned to MI. Hence irradiance in the last hydrated period before sampling is significant for the physiological state of lichens. A standardized irradiance pre-treatment before start of experiments is recommended. [References: 33] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Solhaug KA Norwegian Univ Life Sci, Dept Ecol & Nat Resource Management POB 5003 NO-1432 As Norway Norwegian Univ Life Sci, Dept Ecol & Nat Resource Management NO-1432 As Norway Masaryk Univ, Fac Sci, Inst Expt Biol, Dept Plant Physiol & Anat CS-61137 Brno Czech Republic <36> UI - 2008-307TF-0022 DD - ISI Document Solution: 307TF AU - Liu J AU - He WM AU - Zhang SM AU - Liu FH AU - Dong M AU - Wang RQ MA - dongming@ibcas.ac.cn RA - Dong M TI - Effects of clonal integration on photosynthesis of the invasive clonal plant Alternanthera philoxeroides SO - Photosynthetica. 46(2):299-302, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):299-302 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Alligator weed MH - Biological invasions MH - Chlorophyll fluorescence MH - Clonal plants MH - Net photosynthetic rate MH - Photosystem 2 MH - Nutrient heterogeneity MH - Stomatal conductance MH - Sub-stomatal co2 concentration MH - Transpiration rate. MH - Genetic diversity MH - Alligator weed MH - United-states MH - China MH - Plasticity MH - Growth MH - Availability MH - Temperature MH - Environment MH - Nitrogen. AB - A greenhouse experiment examined whether clonal integration improves photosynthesis of ramets of alligator weed [Alternanthera philoxeroides (Mart.) Griseb.], a widespread invasive clonal plant in China, in heterogeneous (He) nutrient habitats. The connected pairs of ramets experienced different nutrient levels [high homogeneous (Ho) nutrient, low Ho nutrient, and two He nutrient treatments]. Clonal integration significantly improved the net photosynthetic rate, stomatal conductance, transpiration rate, and minimal and maximal chlorophyll fluorescence of ramets of alligator weed in low nutrient condition. These characteristics may contribute to the success of the ramets of alligator weed in invading contrasting habitats. The clonal integration of the invasive clonal plants may contribute significantly to their invasiveness. [References: 30] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Dong M Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change Beijing 100093 Peoples R China Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change Beijing 100093 Peoples R China Shandong Univ, Inst Environm Res Jinan 250100 Peoples R China <37> UI - 2008-307TF-0024 DD - ISI Document Solution: 307TF AU - Yang YQ AU - Yao Y MA - yaoyinan0430@sina.com RA - Yao Y TI - Photosynthetic responses to solar UV-A and UV-B radiation in low-and high-altitude populations of Hippophae rhamnoides SO - Photosynthetica. 46(2):307-311, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):307-311 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Abscisic acid MH - Carotenoids MH - Chlorophyll content and fluorescence MH - Intra-specific response MH - Photosystem 2 MH - Quenching photochemical and non-photochemical MH - Sea buckthorn MH - Relative water content MH - Stomatal conductance MH - Water use efficiency. MH - Carbon isotope discrimination MH - Antarctic vascular plants MH - Water-use efficiency MH - Ultraviolet-b MH - Physiological-responses MH - Field conditions MH - Cucumis-sativus MH - Seedlings MH - Acclimation MH - Growth. AB - Two contrasting sea buckthorn (Hippophae rhamnoides L.) populations from the low (LA) and high (HA) altitudinal regions were employed to evaluate the plant physiological responses to solar UV-A radiation and near-ambient UV-B radiation (UV-B+A) under the sheltered frames with different solar ultraviolet radiation transmittance. LA-population was more responsive to solar UV-A. Some modification caused by UV-A only existed in LA-population, such as significant reduction of leaf size, relative water content, and chlorophyll (Chl) b content as well as delta C-13 elevation, coupled with larger increase of contents of total carotenoids (Cars). This higher responsiveness might be an effective pre-acclimation strategy adapting for concomitant solar UV-B stress. Near-ambient UV-B+A radiation caused significant reduction of leaf size and Chl content as well as slight down-regulation of photosystem 2 activity that paralleled with higher heat dissipation, while photosynthetic rate was modestly but significantly increased. The higher photosynthesis under near-ambient UV-B+A radiation could be related to pronounced increase of leaf thickness and effective physiological modification, like the increase of leaf protective pigments (Cars and UV-absorbing compound), constant high photochemical capacity, and improved water economy. [References: 32] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Yao Y Guizhou Univ, Res Inst Fruit Resources Karst Mt Reg Guiyang 550025 Peoples R China Guizhou Univ, Res Inst Fruit Resources Karst Mt Reg Guiyang 550025 Peoples R China Chongqing Normal Univ, Coll Life Sci Chongqing 400047 Peoples R China <38> UI - 2008-307TF-0026 DD - ISI Document Solution: 307TF AU - Mishra SK AU - Patro L AU - Mohapatra PK AU - Biswal B MA - basanti6@sancharnet.in RA - Biswal B TI - Response of senescing rice leaves to flooding stress SO - Photosynthetica. 46(2):315-317, 2008 Jun. AS - Photosynthetica 2008 Jun;46(2):315-317 PU - SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS. URL: http://www.springeronline.com IS - 0300-3604 MH - Adaptation to stress MH - Carotenoids MH - Chlorophyll MH - Non-photochemical quenching MH - Photosystem 2 MH - Quantum yield MH - Senescence. MH - Chlorophyll-alpha fluorescence MH - Photosystem-ii MH - Water-stress MH - Photoinhibition MH - Metabolism MH - Protein. AB - Flooding stress (FS) induced changes in pigment and protein contents and in photochemical efficiency of thylakoid membranes of chloroplasts were investigated during senescence of primary leaves of rice seedlings. Leaf senescence was accompanied by loss in 2,6-dichlorophenolindophenol (DCPIP) photoreduction, rate of oxygen evolution, quantum yield of photosystem 2 with an increase in MDA accumulation, and non-photochemical quenching (NPQ) of chlorophyll fluorescence. These changes were further aggravated when the leaves during this period experienced FS. The increase in NPQ value under stress may indicate photosynthetic adaptation to FS. [References: 20] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Biswal B Sambalpur Univ, Sch Life Sci, Biochem Lab Jyoti Vihar 768019 Orissa India Sambalpur Univ, Sch Life Sci, Biochem Lab Jyoti Vihar 768019 Orissa India <39> UI - 2008-309HL-0004 DD - ISI Document Solution: 309HL AU - Krupenina NA AU - Bulychev AA AU - Roelfsema MRG AU - Schreiber U MA - kamzolkina-n@yandex.ru RA - Krupenina NA TI - Action potential in Chara cells intensifies spatial patterns of photosynthetic electron flow and non-photochemical quenching in parallel with inhibition of pH banding SO - Photochemical & Photobiological Sciences. 7(6):681-688, 2008. AS - Photochem. Photobiol. Sci 2008;7(6):681-688 PU - ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND. URL: http://www.rsc.org IS - 1474-905X MH - Chlorophyll fluorescence MH - Corallina cells MH - Voltage-clamp MH - Light MH - Chloroplasts MH - Excitation MH - Transport MH - Channels MH - Intact MH - Acid. AB - Characean cells exposed to illumination arrange plasma-membrane H+ fluxes and photosynthesis in coordinated spatial patterns. The limited availability of CO2 in alkaline bands accounts for the lower effective quantum yield of photosystem II (Delta F/F-m') in chloroplasts of these bands compared to acidic zones. The effect of electrically triggered action potential on the spatial distribution of photosynthetic parameters (Delta F/F-m' and non-photochemical quenching, NPQ) and extracellular pH was studied with fluorescence imaging and pH microelectrodes. In the resting cell at a range of light intensities, the periodic profile of extracellular pH is parallel to the profile of NPQ and antiparallel to that of Delta F/F-m'. After triggering the action potential, the pH banding temporarily disappeared, but in contrast, the differences in effective quantum yield and NPQ patterns became more apparent. The transient changes in pH- banding, effective quantum yield and non- photochemical quenching are discussed in relation to alterations in intracellular Ca2+ and H+ concentrations during and after the action potential. [References: 38] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physical Chemistry/Chemical Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2008 week 27 IN - Reprint available from: Krupenina NA Moscow MV Lomonosov State Univ, Fac Biol Moscow 119991 Russia Moscow MV Lomonosov State Univ, Fac Biol Moscow 119991 Russia Univ Wurzburg, Julius von Sachs Inst Biowissensch D-97082 Wurzburg Germany <40> UI - 2008-309OJ-0027 DD - ISI Document Solution: 309OJ AU - Mazzoni M AU - Falorni P AU - Del Bianco S MA - M.Mazzoni@ifac.cnr.it RA - Mazzoni M TI - Sun-induced leaf fluorescence retrieval in the O-2-B atmospheric absorption band SO - Optics Express. 16(10):7014-7022, 2008 May 12. AS - Opt. Express 2008 May 12;16(10):7014-7022 PU - OPTICAL SOC AMER, 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA. URL: http://www.osa.org IS - 1094-4087 MH - Chlorophyll fluorescence. AB - Sun-induced leaf fluorescence was inferred by using high resolution (0.5 cm(-1)) radiance measurements and simulated spectra of the solar irradiance at the ground level, in the region of the O-2-B absorption band. The minimization of a cost function was performed in the Fourier transform domain in order to make an accurate fit of the Instrumental Line-Shape that convoluted the simulated spectrum. Second-order polynomials were used to fit the leaf fluorescence and reflectance in the 100-cm(-1)-wide spectral window. The scale and the instrumental conversion factor were also fitted in order to obtain an accuracy that could not be attained by using the radiance measurements alone. (C) 2008 Optical Society of America. [References: 8] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Applied Physics/Condensed Matter/Materials Science in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2008 week 27 IN - Reprint available from: Mazzoni M CNR, Ist Fis Applicata Nello Carrara Via Madonna del Piano 10 I-50019 Sesto Fiorentino Italy CNR, Ist Fis Applicata Nello Carrara I-50019 Sesto Fiorentino Italy <41> UI - 2008-308LS-0004 DD - ISI Document Solution: 308LS AU - Yotsumoto Y AU - Hasegawa Y AU - Fukuda S AU - Kobayashi H AU - Endo M AU - Fukao T AU - Yamaguchi S MA - yukana@med.shimane-u.ac.jp RA - Yotsumoto Y TI - Clinical and molecular investigations of Japanese cases of glutaric acidemia type 2 SO - Molecular Genetics & Metabolism. 94(1):61-67, 2008 May. AS - Mol. Genet. Metab 2008 May;94(1):61-67 PU - ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA. URL: http://www.apnet.com IS - 1096-7192 MH - Glutaric acidemia type 2 (ga2) MH - Electron transfer flavoprotein (etf) MH - Electron transfer flavoprotein dehydrogenase (etfdh) MH - Organic acidemia MH - Fatty acid metabolism disorder. MH - Electron-transfer flavoprotein MH - Aciduria type-ii MH - Alpha-subunit MH - Ubiquinone oxidoreductase MH - Beta-oxidation MH - Deficiency MH - Fibroblasts MH - Cloning MH - Biosynthesis MH - Phenotypes. AB - Glutaric acidemia type 2 (GA2) is an autosomal recessive disorder resulting from a deficiency of electron transfer flavoprotein (ETF) or ETF dehydrogenase (ETFDH) that manifests from most severe neonatal to late-onset forms. However, the genetic defect responsible for the disease and clinical severity is not well-characterized. In order to understand the relationship between the phenotype and genetic defect, we investigated the clinical and molecular features of 15 Japanese patients, including 4 previously reported cases. Three patients had the neonatal form and 8 patients had the late-onset form, I of whom presented an extremely mild phenotype. Immunoblot analysis showed that either ETF alpha, ETF beta, or ETFDH was significantly reduced or absent in all patients. However, no specific enzyme deficiency predominated, and there were no associations with the clinical severity. Genetic analyses identified 15 mutations including non-sense, missense, splice site mutations, and small deletions, in ETFA, ETFB and ETFDH genes. Although almost all mutations were unique to Japanese patients and no common mutations were found, some of them appeared to be associated with a specific phenotype. Our results suggest that clinical and mutational spectrums of Japanese GA2 patients are heterogeneous and that genetic diagnoses may help to predict a prognosis and provide more accurate diagnostic information for patients and families with GA2. (c) 2008 Elsevier Inc. All rights reserved. [References: 17] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Molecular Biology & Genetics in Current Contents(R)/Life Sciences. EW - 2008 week 27 IN - Reprint available from: Yotsumoto Y Shimane Univ, Sch Med, Dept Pediat 89-1 En Ya Cho Izumo Shimane 6938501 Japan Shimane Univ, Sch Med, Dept Pediat Izumo Shimane 6938501 Japan Gifu Univ, Grad Sch Med, Dept Pediat Gifu 5011194 Japan <42> UI - 2008-307SG-0005 DD - ISI Document Solution: 307SG AU - Mercado JM AU - Ramirez T AU - Cortes D AU - Sebastian M AU - Liger E AU - Bautista B MA - jesus.mercado@ma.ieo.es RA - Mercado JM TI - Partitioning the effects of changes in nitrate availability and phytoplankton community structure on relative nitrate uptake SO - Marine Ecology-Progress Series. 359:51-68, 2008. AS - Mar. Ecol.-Prog. Ser 2008;359:51-68 PU - INTER-RESEARCH, NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY. URL: http://www.int-res.com IS - 0171-8630 MH - Nitrogen uptake MH - Diatoms MH - Phytoplankton MH - Primary production MH - Upwelling MH - Alboran sea MH - Mediterranean sea. MH - Sw mediterranean-sea MH - Nw-alboran sea MH - Nitrogen uptake MH - Equatorial pacific MH - Ammonium uptake MH - Coastal waters MH - Upwelling area MH - Size-structure MH - High-nutrient MH - St-lawrence. AB - The uptake of dissolved nitrogen by different assemblages of phytoplankton was determined during 4 seasonal surveys carried out in the northwest sector of the Alboran Sea. The study area was characterized by stratification of the water column from spring to autumn, leading to very low nutrient concentrations in the euphotic zone; in particular, nitrate was below the detection limit at numerous stations in autumn. In winter and spring, the potential limitation of phytoplankton growth by nitrate was alleviated at some stations by upwelling of the nutrient-enriched Levantine Intermediate Water (LIW). The values of relative NO3- uptake (the proportion of nitrate to total N uptake) were highly variable (ranging from 0.01 to 0.8), even during single surveys. At most of the sampling stations during the stratification period, the relative nitrate uptake was < 0. 2 at the surface, but increased at the depth of the sub-surface chlorophyll a fluorescence maximum (SFM). At the surface, relative nitrate uptake and nitrate concentrations were strongly correlated, and about 82 % of the relative nitrate uptake variability was accounted for by simultaneous changes in the nitrate concentrations and the micro-plankton chlorophyll a size fractions. These changes were related to modifications in upwelling intensity, as determined by variability in surface salinity. In contrast, relative nitrate uptake was not correlated with nitrate concentrations in the SFM samples, where the mean nitrate concentration increased 3-fold with respect to the surface value. On average, the micro-phytoplankton in these samples collected at the SFM was dominated by diatoms, the abundance of which ranged from 24 to 960 cells ml(-1). This variability in diatom cell abundance explained about 52 % of the variability of relative nitrate uptake at this depth level. Therefore, our data demonstrate that the proposed relationship between relative nitrate uptake and large phytoplankton was most evident at non-limiting nitrate concentrations. [References: 60] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Mercado JM Ctr Oceanog Malaga, Inst Espanol Oceanog Puerto Pesquero S-N,Apdo 285 Fuengirola Malaga 29640 Spain Ctr Oceanog Malaga, Inst Espanol Oceanog Fuengirola Malaga 29640 Spain Univ Malaga, Fac Ciencias, Dept Ecol Malaga 29074 Spain Univ Malaga, Dept Fis Aplicada 2, ETSI Informat E-29071 Malaga Spain <43> UI - 2008-309ZD-0003 DD - ISI Document Solution: 309ZD AU - Rienecker E AU - Ryan J AU - Blum M AU - Dietz C AU - Coletti L AU - Marin R AU - Bissett WP MA - erich@mbari.org RA - Rienecker E TI - Mapping phytoplankton in situ using a laser-scattering sensor SO - Limnology & Oceanography Methods. 6:153-161, 2008 Mar. AS - Limnol. Oceanogr. Meth 2008 Mar;6:153-161 PU - AMER SOC LIMNOLOGY OCEANOGRAPHY, 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA IS - 1541-5856 MH - Particle-size MH - Light-scattering MH - Instrument MH - Sediments MH - Patterns. AB - A primary limitation of phytoplankton ecology research is the difficulty of describing patchiness and distributions of different phytoplankton groups. Chlorophyll fluorescence and optical backscatter are useful measurements that provide information about phytoplankton, but these measurements do not allow distinction of phytoplankton taxa. Traditional phytoplankton identification methods (such as microscopy, HPLC analysis, and flow cytometry) are labor intensive and therefore can provide only very limited coverage and resolution. Through lab experiments we show that the Laser In Situ Scattering and Transmissometer (LISST-100) instrument can accurately quantify phytoplankton cell dimensions for some cell shapes. Pseudo-spherical dinoflagellates are described with a single peak in the particle size distribution (PSD) at the cross-sectional dimension of the cells. Pennate diatoms are described with peaks in the PSD at the major and minor axis dimensions of the cells. Diatom cells with minor axis dimensions that vary along the major axis are described with one peak across the range of minor axis dimensions and a second peak at the major axis dimension. Through field experiments, we show that mapping the PSD in situ at high resolution permits description of patchiness and evolution of phytoplankton populations. We present two examples: (1) growing dominance of Ceratium species during a red tide bloom, and (2) concentration of Pseudo-nitzschia australis, a harmful algal bloom (HAB) species, at a water mass front. We conclude that synoptic mapping of the PSD can significantly advance phytoplankton ecology research in the coastal ocean. [References: 25] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Rienecker E Monterey Bay Res Inst 7700 Sandholdt Rd Moss Landing, CA 95039 USA Monterey Bay Res Inst Moss Landing, CA 95039 USA Florida Environm Res Inst Tampa, FL 33612 USA <44> UI - 2008-309ZK-0022 DD - ISI Document Solution: 309ZK AU - Six C AU - Finkel ZV AU - Rodriguez F AU - Marie D AU - Partensky F AU - Campbell DA MA - dcampbell@mta.ca RA - Campbell DA TI - Contrasting photoacclimation costs in ecotypes of the marine eukaryotic picoplankter Ostreococcus SO - Limnology & Oceanography. 53(1):255-265, 2008 Jan. AS - Limnol. Oceanogr 2008 Jan;53(1):255-265 PU - AMER SOC LIMNOLOGY OCEANOGRAPHY, 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA IS - 0024-3590 MH - Free-living eukaryote MH - Photosystem-ii MH - Synechococcus-elongatus MH - Photosynthetic activity MH - Angstrom resolution MH - Light MH - Prasinophyceae MH - Photoprotection MH - Prochlorococcus MH - Acclimation. AB - Ostreococcus, the smallest known marine picoeukaryote, includes low- and high-light ecotypes. To determine the basis for niche partitioning between Ostreococcus sp. RCC809, isolated from the bottom of the tropical Atlantic euphotic zone, and the lagoon strain Ostreococcus tauri, we studied their photophysiologies under growth irradiances from 15 mu mol photons m(-2) s(-1) to 800 mmol photons m(-2) s(-1) with a common nutrient replete regime. With increasing growth irradiance, both strains down-regulated cellular chlorophyll a and chlorophyll b (Chl a and Chl b) content, increased xanthophyll de-epoxidation correlated with nonphotochemical excitation quenching, and accumulated lutein. Ribulose-1,5-bisphosphate carboxylase/oxygenase content remained fairly stable. Under low- growth irradiances of 15-80 mu mol photons m(-2) s(-1), O. sp. RCC809 had equivalent or slightly higher growth rates, lower Chl a, a higher Chl b : Chl a ratio, and a larger photosystem II (PSII) antenna than O. tauri. O. tauri was more phenotypically plastic in response to growth irradiance, with a larger dynamic range in growth rate, Chl a, photosystem cell content, and cellular absorption cross-section of PSII. Estimating the amino acid and nitrogen costs for photoacclimation showed that the deep-sea oceanic O. sp. RCC809 relies largely on lower nitrogen cost changes in PSII antenna size to achieve a limited range of sigma-type light acclimation. O. sp. RCC809, however, suffers photoinhibition under higher light. This limited capacity for photoacclimation is compatible with the stable low- light and nutrient conditions at the base of the euphotic layer of the tropical Atlantic Ocean. In the more variable, high-nutrient, lagoon environment, O. tauri can afford to use a higher cost n-type acclimation of photosystem contents to exploit a wider range of light. [References: 48] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Campbell DA Mt Allison Univ 63B York St Sackville NB E0A 3C0 Canada Mt Allison Univ Sackville NB E0A 3C0 Canada Univ Paris 06 F-29682 Roscoff France CNRS, Biol Stn, UMR 7144 F-29682 Roscoff France <45> UI - 2008-309ZK-0025 DD - ISI Document Solution: 309ZK AU - Moore CM AU - Mills MM AU - Langlois R AU - Milne A AU - Achterberg EP AU - La Roche J AU - Geider RJ MA - cmm297@noc.soton.ac.uk RA - Moore CM TI - Relative influence of nitrogen and phosphorus availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean SO - Limnology & Oceanography. 53(1):291-305, 2008 Jan. AS - Limnol. Oceanogr 2008 Jan;53(1):291-305 PU - AMER SOC LIMNOLOGY OCEANOGRAPHY, 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA IS - 0024-3590 MH - Cyanobacterium prochlorococcus-marinus MH - Sargasso sea MH - Cell-cycle MH - Environmental gradients MH - Elemental stoichiometry MH - Community structure MH - Nutrient stress MH - Pacific-ocean MH - Chlorophyll-b MH - Time-series. AB - Nutrient addition bioassay experiments were performed in the low-nutrient, low-chlorophyll oligotrophic subtropical North Atlantic Ocean to investigate the influence of nitrogen (N), phosphorus (P), and/or iron (Fe) on phytoplankton physiology and the limitation of primary productivity or picophytoplankton biomass. Additions of N alone resulted in 1.5-2 fold increases in primary productivity and chlorophyll after 48 h, with larger (similar to threefold) increases observed for the addition of P in combination with N (NP). Measurements of cellular chlorophyll contents permitted evaluation of the physiological response of the photosynthetic apparatus to N and P additions in three picophytoplankton groups. In both Prochlorococcus and the picoeukaryotes, cellular chlorophyll increased by similar amounts in N and NP treatments relative to all other treatments, suggesting that pigment synthesis was N limited. In contrast, the increase of cellular chlorophyll was greater in NP than in N treatments in Synechococcus, suggestive of NP co-limitation. Relative increases in cellular nucleic acid were also only observed in Synechococcus for NP treatments, indicating co-limitation of net nucleic acid synthesis. A lack of response to relief of nutrient stress for the efficiency of photosystem II photochemistry, F-v:F-m, suggests that the low nutrient supply to this region resulted in a condition of balanced nutrient limited growth, rather than starvation. N thus appears to be the proximal (i.e. direct physiological) limiting nutrient in the oligotrophic sub-tropical North Atlantic. In addition, some major picophytoplankton groups, as well as overall autotrophic community biomass, appears to be co-limited by N and P. [References: 59] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2008 week 27 IN - Reprint available from: Moore CM Univ Southampton, Natl Oceanog Ctr, Sch Ocean & Earth Sci Southampton SO14 3ZH Hants England Univ Essex, Dept Sci Biol Colchester CO4 3SQ Essex England Leibniz Inst Meereswissensch Kiel Germany Univ Plymouth, Sch Earth Ocean & Environm Sci Plymouth PL4 8AA Devon England Marine Biol Assoc UK Plymouth PL1 2PB Devon England Univ Southampton, Natl Oceanog Ctr, Sch Ocean & Earth Sci Southampton SO14 3ZH Hants England Stanford Univ, Dept Geophys Stanford, CA 94305 USA <46> UI - 2008-309ZK-0026 DD - ISI Document Solution: 30