1. Front Cover.cdr - CORE

Recommendations

Info

A B S T R A C T B O O K – A B S T R A C T S O F P O S T E R S In light reactions of photosynthesis electrons are transferred in a linear fashion from water to NADP + , which is reduced to NADPH by ferredoxin-NADP + -oxidoreductase (FNR). In Arabidopsis thaliana two distinct genes, At5g66190 and At1g20020, encode the chloroplast targeted isoforms, FNR1 and FNR2. Both exist as membrane bound and soluble forms. We have investigated physiological roles of FNR using single and double knock-out mutants. Single mutant plants were highly viable suggesting that both isoforms are functional and participate in linear and cyclic electron transfer. Nonetheless, FNR1 isoform is needed for the membrane binding of FNR2, which suggests FNR heterodimer formation. Viability of fnr1 mutants having only soluble FNR proves that soluble form is photosynthetically active. The fnr1xfnr2 (F1 generation) plants were slow-growing due to downregulated photosynthetic capacity. High excitation pressure in the fnr1xfnr2 plants points to over-reduction of electron transfer chain, which was partly discharged via induction of cyclic electron transfer. Scarcity of FNR led to induction of oxidative stress, which induced protective mechanisms in mutant plants. The fnr1 fnr2 plants (F2 generation) lacking both FNR isoforms survived only under heterotrophic conditions. Their photosynthetic machinery was extremely downregulated, but yet their leaves contained a few deformed plastids. MITOCHONDRIAL D-2-HYDROXYGLUTARATE DEHYDROGENASE PARTICIPATES IN AN ALTERNATIVE PATHWAY OF RESPIRATION AND LINKS PHOTORESPIRATION AND THE TRICARBOXYLIC ACID CYCLE Anke Kuhn, Martin K.M. Engqvist, Judith Wienstroer, Andreas P.M. Weber, Veronica G. Maurino Institute for Developmental- and Molecular Biology of Plants, Heinrich-Heine-University, Düsseldorf, Germany E-mail: Veronica.Maurino@uni-duesseldorf.de D-2-hydroxyglutarate (D-2HG) is a dicarboxylic acid with the hydroxy group in the alpha-carbon. Locus At4g36400 encodes a mitochondrial D-2HG dehydrogenase (D-2HGDH) which specifically converts D-2HG into into 2-oxoglutarate (2-OG). In wild-type plants the activity of D-2HGDH increases gradually during developmental and dark-induced senescence while D-2HG accumulates to very high levels under these conditions in loss-of-function mutants. Gene coexpression analysis indicated that D-2HGDH is in the same network as several genes involved in the mobilization of alternate substrates from proteolysis and/or lipid degradation, the electron transfer protein (ETF) and the ETF-ubiquinone oxidoreductase (ETFQO). This and the fact that AtD-2HGDH does not effectively use cytochrome c nor NAD(P) as electron acceptors indicate that AtD-2HGDH may donate electrones to the mitochondrial electron transport chain through ETF/ETFQO. Moreover, a metabolic characterization indicated that D-2HG originates during the catabolism of lysine. On the other hand, D-2HG accumulates to high levels in the photorespiratory mutant lacking serinehydroxymethyl-transferase (shm1) after transfer from high CO2 atmosphere to normal air conditions only in the light. This was accompanied by a huge accumulation of 2-OG and glycine. Probably, in vivo the activity of AtD-2HGDH is inhibited by these metabolites as both inhibited the activity of the recombinant enzyme. CA(II)-BINDING PROTEINS, CCAP1 AND CCAP2, ARE INDUCED BY A LONG DARK PERIOD IN ARABIDOPSIS THALIANA Yuya Ouchi 1 , Akira Nagatani 2 , Masayoshi Maeshima 1 1 Nagoya University, Nagoya, Japan 2 Kyoto University, Kyoto, Japan E-mail: ouchi.yuya@g.mbox.nagoya-u.ac.jp We found novel Ca(II)-binding proteins in A. thaliana: namely, CCaP1 (cytoplasmic Ca(II)-binding protein) and CCaP2. These proteins have no common motif found in other proteins or enzymes. CCaP proteins are localized in the cytoplasm when expressed as GFP-fusion proteins. The promoter-GUS analysis revealed that CCaP1 was predominantly expressed in petioles and CCaP2 in roots. When plants were grown in the dark for >20 h, the mRNA levels of CCaP1 and CCaP2 were increased approximately 10-fold of that of the daytime level. These high level expression were decreased to the daytime level by light illumination for
A B S T R A C T B O O K – A B S T R A C T S O F P O S T E R S of CCaP2 expression in the dark, we cut shoots off and quantified the mRNA. There was no induction of CCaP2 by dark, suggesting that induction of CCaP2 expression needs the signal from shoot. Moreover, we will report the gene-expression profiles in ccap1 and ccap2 mutant lines. FUNCTION OF CDT1 PROTEINS IN GAMETOPHYTE DEVELOPMENT AND S-PHASE CHECKPOINT Séverine Domenichini 1 , Moussa Benhamed 1 , Gert de Jaeger 2 , Sophie Blanchet 1 , Lieven de Veylder 2 , Catherine Bergounioux 1 , Cécile Raynaud 1 1 Institute of Plant Biology, Université Paris XI, Paris, France 2 VIB, Ghent University, Ghent, Belgium E-mail: cecile.raynaud@u-psud.fr CDT1 proteins are involved in S-phase initiation in all eukaryotes: it is a sub-unit of the pre-replication complex (pre-RC) that allows the firing of replication origins. Previous work has established that this function is conserved in Arabidopsis, although AtCDT1a appears to have a dual role in cell cycle regulation and chloroplast division. Here we show that unlike other sub-units of the pre-RC, AtCDT1a is strictly required for female gametophyte development. Male gametophyte development is not completely arrested in cdt1a hemizygous mutants, but some pollen grains die before anther dehiscence. By contrast, cdt1b null mutants have no phenotype, but loss of cdt1b further reduces pollen viability in cdt1a hemizygous plants. Furthermore, we show that AtCDT1 proteins could be involved in the perception or repair of double-strand breaks. Indeed, both AtCDT1a and AtCDT1b interact with DNA-polymerase epsilon, which functions both to replicate the leading strand during S-phase, and in the S-phase check-point. Furthermore, CDT1-RNAi plants are more sensitive to gamma-irradiation than the wild type, and accumulate more double-strand breaks. Taken together, our results indicate that CDT1 function is crucial to genome stability not only because of its role in S-phase onset, but also via a role in the monitoring of DNA integrity. CONIFERYL ALCOHOL AND POTASSIUM IODIDE AFFECT THE CELL VIABILITY OF NON- LIGNIFYING NICOTIANA TABACUM BY-2 CELLS Enni Väisänen 1 , Teemu Teeri 2 , Kurt Fagerstedt 1 , Anna Kärkönen 2,3 1 Department of Biosciences, Division of Plant Biology, University of Helsinki, Helsinki, Finland 2 Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland 3 MTT Agrifood Research Finland, Jokioiken, Finland E-mail: enni.vaisanen@helsinki.fi In lignifying cells monolignols are produced in the cytosol, deposited into the cell wall and polymerized to lignin. It has been suggested that monolignol alcohols are toxic, but the experimental evidence to support this claim is hard to find. We have tested monolignol toxicity by treating non-lignifying Nicotiana tabacum BY-2 cells in liquid culture with 50 µM - 2 mM monolignol coniferyl alcohol (CA) with or without 5 mM potassium iodide (KI) supplementation, which prevents lignification by catalyzing H2O2 removal. It was observed that CA treatment alone rarely affected cell viability. In contrast, KI treatment greatly reduced cell viability. In combined treatments with KI and 2 mM CA cell viability was lower than with KI only. These results suggest that the hypothesis on monolignol toxicity is plausible. However, in combined treatments with KI and 500 µM CA the cell viability was higher than with KI only. Similar effects on growth were observed in preliminary experiments, where N. benthamiana seeds were germinated in liquid cultures supplemented with KI and CA. The unexpected effects of KI and KI + CA raise questions about the biochemical reactions that take place during the treatments. CHARACTERIZATION OF A GLYCOSIDE HYDROLASE WITH RESPECT TO THE BIOSYNTHESIS OF ARABINOGALACTAN PROTEINS Eva Knoch 1 , Henriette L. Petersen 1 , William Willats 1 , Satoshi Kaneko 2 , Henrik V. Scheller 3 , Naomi Geshi 3 1 Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark 62 X X I V S P P S C O N G R E S S 2 0 1 1
Page 1 and 2:
��
Page 3 and 4:
Foreword eword ord A B S T R A C T
Page 5 and 6:
Program of the Congress gram of the
Page 7 and 8:
A B S T R A C T B O O K - P R O G R
Page 9 and 10:
A B S T R A C T B O O K - P R O G R
Page 11 and 12: Plenary session 1 A B S T R A C T B
Page 13 and 14: Plenary session 2 THE BIOLOGY OF AL
Page 15 and 16: Session 1. Biotechnology and synthe
Page 17 and 18: Session 1. Biotechnology and synthe
Page 19 and 20: Session 2. Systems biology and -omi
Page 21 and 22: Session 2. Systems biology and -omi
Page 23 and 24: A B S T R A C T B O O K - A B S T R
Page 27 and 28: Pleanary session 4 A B S T R A C T
Page 29 and 30: Invited talk 4 A B S T R A C T B O
Page 31 and 32: Session 5.Cell biology A B S T R A
Page 33 and 34: Session 6.Organelle biology A B S T
Page 35 and 36: Session 6.Organelle biology A B S T
Page 37 and 38: Session 7.Development A B S T R A C
Page 39 and 40: Session 8.Signalling A B S T R A C
Page 41 and 42: Pleanary session 6 A B S T R A C T
Page 51 and 52: Session 13.Pathogen defense and pla
Page 53 and 54: Session 13.Pathogen defense and pla
Page 61: A B S T R A C T B O O K - A B S T R
Page 67 and 68: Sapporo Medical University, Sapporo
Page 91 and 92: SCF = A B S T R A C T B O O K - A B
Page 93 and 94: A B S T R A C T B O O K - L I S T O
Page 95 and 96: A B S T R A C T B O O K - L I S T O
Page 97 and 98: Sponsors onsors ors A B S T R A C T
show all

1. Front Cover.cdr - CORE

Create successful ePaper yourself

Delete template?

Save as template?