Book of Abstracts - Geyseco

More documents

Recommendations

Info

P - Posters P08-005: HEAT DISSIPATION IN THE MOSS PHYSCO- MITRELLA PATENS: EVOLUTION OF PROTECTION MECHANISMS UPON LAND COLONIZATION Morosinotto, T. - Gerotto, C. - Alboresi, A. - Giacometti, G. - Bassi, R. Università di Verona Light is the source of energy for photosynthetic organisms but, when in excess, it also drives the formation of reactive oxygen species and consequently photoinhibition. Plants and algae, thus, have evolved mechanisms to regulate light harvesting efficiency in response to variable light intensities as to avoid oxidative damage. Non Photochemical Quenching (NPQ) consists in the rapid dissipation of excess excitation energy as heat. Although widespread among oxygenic photosynthetic organisms, NPQ shows important differences in its machinery: in land plants, such as Arabidopsis thaliana, it depends on the presence of PsbS, while a different protein, called LHCSR (or Li818), is required in the green alga Chlamydomonas reinhardtii. The moss Physcomitrella patens is the only known organism where both proteins are present. By generating knock out mutants lacking PSBS and/or LHCSR we demonstrated that both gene products are active in P. patens NPQ. Plants lacking both proteins are also more susceptible to high light stress, implying that these gene products are indeed fundamental for photoprotection. Furthermore, generation of plants over-expressing either PsbS or LHCSR also showed that these proteins are active independently in triggering NPQ. Taken together, these results suggest that NPQ is a fundamental mechanism for survival in excess light and that upon land colonization photosynthetic organisms evolved a new mechanism for excess energy dissipation before losing the ancestral one found in algae. P08-006: FUNCTIONAL ANALYSIS OF ALB3 IN THE CPSRP-DEPENDENT LHCP TRANSPORT TO THE THYLAKOID MEMBRANE OF CHLOROPLAST Schünemann D Ruhr University Bochum, Molecular Biology of Plant Organells *Corresponding author, e-mail: danja.schuenemann@rub.de Alb3 belongs to the recently identified YidC/Oxa1/Alb3 protein family that facilitates the insertion and assembly of membrane proteins in bacteria, mitochondria and chloroplasts. In chloroplasts, the signal recognition particle (cpSRP) and its receptor cpFtsY form a complex with the translocase Alb3 during the posttranslational insertion of members of the light-harvesting chlorophyll-binding proteins (LHCPs) into the thylakoid membrane. CpSRP consists of an evolutionarily conserved 54-kD subunit (cpSRP54) and a unique 43-kD subunit (cpSRP43) (1). In this study we showed an interaction between full-length Alb3 and cpSRP43 and analysed the binding interface. We used a combination of in vivo techniques as bimolecular fluorescence complementation using Arabidospsis protoplasts and the yeast split ubiquitin system and in vitro techniques using Alb3-proteoliposomes. In addition we present data to analyse the interplay of the SRP pathway components at the Alb3-translocase that lead to release of LHCP and recycling of the SRP components.(1) Schünemann D. (2007) Mechanisms of protein import into thylakoids of chloroplasts. Biol. Chem., 388: 907-915 P08-007: EFFECTS OF LIGHT INTENSITY ON PHOTOS- YNTHESIS DURING ACCLIMATIZATION OF U. MINOR Dias, M.* - Pinto, G. - Correia, C. - Moutinho-Pereira, J. - Guerra, C.C. - Monteiro, C. - Santos, C. CESAM, University of Aveiro *Corresponding author, e-mail: celeste.dias@ua.pt Ulmus spp. is among the Europe´s Noble Hardwoods. It is important as a source of high quality wood and is largely used for landscape and amenity purposes. However, elm population faces a drastic decline since the beginning of the 20th century due to the Dutch Elm Disease. Several efforts have been performed for preserving elm species and research dealing with in vitro propagation has been successfully conducted. Although acclimatization of micropropagated Ulmus minor was already achieved, no comprehensive study on the physiological responses has been done. The goal of this study is to optimize light acclimatization conditions for the maximization of plant performance. Hence, this contribution aims to reduce plant losses and to establish and optimize large scale breeding programmes. In our experiments, we transferred plants growing under in vitro conditions to ex vitro and acclimatized under low and high light condition. We analysed the effects of light intensity on plant performance through the measurement of photosynthesis, chlorophyll fluorescence, RuBisCO activity, pigments and carbohydrates in leaves under in vitro conditions and after 7, 14, 25 and 42 days of ex vitro transfer. Under in vitro conditions, U. minor leaves presented a positive photosynthetic response. The results obtained during the acclimatization indicate a different behavior of U. minor in response to different irradiance. Plants acclimatized under high light conditions have a more positive effect on plant performance than those under low light conditions. Acknowledgements This work was supported by Portuguese Foundation for Science and Technology (FCT) through a post-doctoral fellowship of M. C. Dias (SFRH/BPD/41700/2007) and a doctoral fellowship of C. Monteiro (SFRH/BD/48204/2008&rlm;). P08-008: DROUGHT ADAPTATION MECHANISMS: THE BENEFICIAL INTERACTION OF PHOTOSYNTHESIS AND RESPIRATION IN NICOTIANA SYLVESTRIS Galle, A. 1 * - Flexas, J. 1 - Florez-Sarasa, I. 1 - Thameur, A. 2 - De Paepe, R. 3 - Medrano, H. 1 - Ribas-Carbo, M. 1 1 Universitat de les Illes Balears 2 Laboratory of Dryland and Oasis Cropping, Institute of the Arid Regions of Medenine, 4119 Elfjé, Tunisia 3 Laboratoire Mitochondries et Métabolisme, Institut de Biotechnologie des Plantes (IBP), UMR-CNRS 8618, Batiment 630, Université Paris Sud, F-91405 Orsay cedex, France * Corressponding autor e-mail: alexander.galle@uib.es More frequent drought events will impair plant carbon balance and thus primarily affect photosynthesis and respiration. Due to their close interconnection, an improved plant adaptation to drought and survival may be derived from the beneficial interactions of photosynthetic and respiratory processes. Nicotiana sylvestris plants were grown under different environmental conditions (indoors & outdoors), subjected to severe drought stress by withholding water and thereafter re-watered until photosynthesis recovered. In vivo photosynthetic and respiratory pathway activities, as well as related leaf compounds were determined. The response to drought and re-watering was similar under all growth conditions, while the rate of decline in net photosynthesis and respiration differed among them. Moreover, mitochondrial respiratory pathway activities were different in outdoors and indoors experiments, most likely to adjust ATP supply for maintained cell functioning. Additional data on mitochondrial complex I mutants (CMSII) support the essential role of respiratory ATP supply during drought-inhibited photosynthesis. Further implications on photosynthetic limitations and the rate of recovery are discussed. P08-009: SALICYLIC ACID-INDUCED CHANGES IN PHOTOSYSTEM II REACTIONS IN BARLEY PLANTS Losanka Popova Staevska Institute of Plant Physiology, Bulgarian Academy of Sciences *Corresponding author, e-mail: lpopoba@bio21.bas.bg In vivo effect of salicylic acid (SA) on PSII reaction activity P
FESPB 2010 - XVII Congress of the Federation of European Societies of Plant Biology in barley (Hordeum vulgare L.) was assessed by monitoring of Hill reaction activity, kinetic behavior of oxygen evolving centers, thermoluminescence emission and polypeptide analysis of thylakoid membranes. Increasing concentrations of SA (0.1mM, 0.5 mM and 1mM), imposed through the root medium for a period of 7 days have a marked inhibitory effect on the number and the energetics of PSII alfa reaction centers that is consistent with some specific alterations in polypeptide composition of thylakoid membranes. On the other hand, when barley seedlings were supplied with SA through the transpiration stream for 24 h no marked changes in investigated parameters were observed. The results obtained are in support of the idea that SA, applied exogenously to the root medium, acts as moderate stressor having a direct effect on photosynthetic apparatus and on the PSII reactions in particular. A possible role of PSII β centers situated in stroma lamellae regions is discussed. P08-010: PHYTOTOXICITY OF THE PLANT SECON- DARY METABOLITE TRANS-CHALCONE CAN BE DE- TECTED BY IMAGING OF CHLOROPHYLL A FLUO- RESCENCE Graña, E. - Sotelo, T. - Sánchez-Moreiras, A.M. - Reigosa, M.J. University of Vigo *Corresponding author, e-mail: eli-grana@uvigo.es Chalcone (1,3-diphenyl-2-propen-1-one) is an aromatic ketone, precursor of important molecules in plants, like flavonoids or anthocyanins. This compound has been found to show phytotoxic activity1, but no deeply studies were done to elucidate the mode of action of this compound on adult plants. Therefore, we tested the phytotoxic effect of different chalcone concentrations by watering or spraying for 21 days on Arabidopsis thaliana plants. Plants were analyzed every day to obtain Y(II) (effective PS II quantum yield), Y(NO) (quantum yield of non-regulated energy dissipation), Y(NPQ) (quantum yield of regulated energy dissipation), Fv/Fm (maximal PS II quantum yield), ETR(electron transport rate), qN and qL coefficients (nonphotochemical and photochemical quenching, respectively). We observed growth reduction and bolting rosettes in chalconewatered plants. In addition to these morphological changes we found an increase in Y(NO), closely linked with a decrease in Y(II) and electron transport rate (ETR), while no effects were detected in Y(NPQ) and Fv/Fm. This could suggest a slowing down in Calvin cycle, induced by an energy diversion to reproduction in detriment of growth. The results previously found for chalcone-watered plants in Y(II), Y(NO), Y(NPQ) and ETR were also found in chalcone-sprayed plants. However, Fv/Fm showed a highly significant decrease after spraying, which could be suggesting a physical damage at the antenna complex and a concomitant effect on the photochemical phase of the photosynthetic process. The previously discussed results confirm the phytotoxic activity of chalcone on adult plants and its potential use on weed management. 1: Chen WJ, Yun MS, Deng F, and Yogo Y. 2004. Weed Biol. Manage. Vol4, 235-238. P08-011: DETECTION OF PHOTOSYNTHETICALLY- GENERATED REACTIVE OXYGEN SPECIES USING NOVEL SPIN-TRAPS: THE BENEFITS OF THE ENCAP- SULATION OF SPIN-TRAP ADDUCTS BY CYCLODEX- TRINS Šnyrychová, I. 1 * - Stolze, K. 2 1 Palacky University Olomouc, Faculty of Science, Dept. of Experimental Physics, Laboratory of Biophysics 2 Molecular Pharmacology and Toxicology Unit, Department of Biomedical Sciences, University of Veterinary Medicine Vienna *Corresponding author, e-mail: snyrychi@prfnw.upol.cz Electron paramagnetic resonance (EPR) spin trapping spectroscopy is one of the best methods that can be used for the detection of oxygen radicals, however, its application in biological systems is limited by the instability of spin trap adducts. This instability is caused namely by the reduction of paramagnetic spin trap adducts to EPR silent species by the action of biological reductants. It has been suggested that this undesirable reduction can be partially avoided by the inclusion of the spin trap adducts into the cavity of cyclic oligosaccharides - cyclodextrins. A recent study with spin trap EMPO has already proven that the presence of cyclodextrins can considerably improve the sensitivity of superoxide detection in illuminated photosystem II particles [1]. In our current work we have tested several novel spin traps with respect to their ability to trap photosynthetically-generated oxygen radicals and we have evaluated the extent of the stabilization of their spin adducts by various cyclodextrins. [1] Šnyrychová I. (2010) Free Radic Biol Med 48:264-274 Acknowledgement: I.Š. was supported by the grant MŠMT ČR MSM 6198959215. P08-012: SPECIFIC SUPPRESSION OF THE CHLORO- PLAST N-GLYCOSYLATED CARBONIC ANHYDRASE (CAH1) HAS MAJOR IMPACT ON THE PHOTOSYN- THETIC PERFORMANCE OF ARABIDOPSIS THALIA- NA Ortega-Villasante, C. 1 * - Burén, S. 2 - Blanco-Rivero, A. 1 - Samuelsson, G. 2 - Villarejo, A. 1 1 Universidad Autónoma de Madrid 2 Umeå Plant Science Centre *Corresponding author, e-mail: cristina.ortega@uam.es A recently described alpha-type carbonic anhydrase (CAH1) has been localized in the Arabidopsis thaliana chloroplast after being N-glycosylated in the endomembrane system. Although its trafficking pathway to the chloroplast through the endoplasmic reticulum and the Golgi apparatus has been studied in some detail, the function of this protein remains unknown. Genomic analysis with bioinformatic tools annotated CAH1 to a cluster involved in chloroplast development and photosynthesis. To unravel eventual role of CAH1 in photosynthesis, we have used T-DNA knockout mutant lines of Arabidopsis in which the expression of the CAH1 gene was suppressed. Mature plants of two mutant alleles exhibited reduced CO2 exchange rates as well as lower accumulation of starch, suggesting that CAH1 may play a crucial role in the photosynthetic performance of the plant. Plants from a mutant allele with stronger photosynthetic phenotype were also affected in growth and showed altered levels of soluble carbohydrates linked to chloroplast function. To complement the mutant phenotype, different epitope-tagged versions of CAH1 were expressed in the suppressed plants. Interestingly, N-terminally tagged CAH1 could fully restore wild-type levels of starch and photosynthesis, while expression of the C-terminally tagged protein had little or no complementary effect. Our results indicate that complementation was only achieved when the tagged CAH1 protein was correctly targeted to the chloroplast, and that tagging of the C-terminus inhibited this process. The data also suggest that CAH1 plays a pivotal role in the photosynthetic performance of the plant cell, despite the fact of being a very low abundant protein in the stroma. P08-013: SUPRAMOLECULAR COMPLEXES AND CAL- VIN CYCLE REGULATION: THE INITIAL STEP OF GA- PDH/CP12/PRK COMPLEX FORMATION COMES TO LIGHT Sparla, F. 1 - Thumiger, A. 1 - Fermani, S. 1 - Trivelli, X. 2 - Marri, L. 1 - Pupillo, P. 1 - Falini, G. 1 - Trost, P. 1 1 University of Bologna 2 University of Lille In oxygenic photosynthetic organisms, the activities of two Cal-
Page 4:
FESPB 2010 - XVII Congress of the F
Page 7 and 8:
PLENAR SESSION LECTUR
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
PARALL SESSION LECTUR
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
POST 04 POSTERS • Environmental S
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78: FESPB 2010 - XVII Congress of the F
Page 127: FESPB 2010 - XVII Congress of the F
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 206 and 207:
Author Index Aarts, M.G. S18-002 Ab
Page 208 and 209:
Cattivelli, L. P01-031 Cawly, J. P1
Page 210 and 211:
Gallego, B. P17-037 Gallego, P.P. P
Page 212 and 213:
Kersten, B. P10-017 Keskin, O. P05-
Page 214 and 215:
Miguel, C. S02-001, P01-122 Milhinh
Page 216 and 217:
Ramiro, M. P09-018 Ramon, M P13-002
Page 218 and 219:
Tanimoto, E. P01-045 Tarakanov, I.
show all

Book of Abstracts - Geyseco

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?