Book of Abstracts - Geyseco

More documents

Recommendations

Info

P06 Root Biology P06-001: THE SHR/SCR PATHWAY DIRECTLY ACTIVA- TES GENES INVOLVED IN ASYMMETRIC CELL DIVI- SION IN THE ARABIDOPSIS ROOT Sozzani, R. 1 * - Moreno Risueno, M. 1 - Wolfgang Busch 1 - Jaimie Van Norman 1 - Walter Dewitte 1 - Jim Murray 1 - Philip Benfe 1 1 (Duke University) 2 (Cardiff School Of Biosciences) *Corresponding author e-mail: rs93@duke.edu Multicellular organisms rely on asymmetric cell division to generate diverse cell types. The molecular mechanisms responsible for this process are still poorly understood, in particular how developmental pathways trigger asymmetric divisions. Asymmetric divisions in the Arabidopsis root are controlled by a finely orchestrated interplay between the transcription factors SHOR- TROOT (SHR) and SCARECROW (SCR). To understand the dynamics of the SHR/SCR regulatory network, we performed time-course microarrays after SHR and SCR induction. To examine the transcriptional effects specifically to the ground tissue, we sorted the GFP positive cells from the J0571 enhancer trap present in both inducible lines. The proportion of transcription factors downstream of SHR/SCR network was significantly higher than expected by chance, as demonstrated by GO category enrichment. Thus, this suggests that SHR and SCR activate a regulatory cascade involved in several biological processes including asymmetric cell division. Moreover, we observed that that joint activity by both SHR and SCR is necessary to activate this group of genes and that their temporal regulation is important to determine the timing of asymmetric cell division in the ground tissue. P06-002: LONGITUDINAL AND TRANSVERSAL EXPAN- SION IN RESPONSE TO INCREASED ETHYLENE IN MAIZE ROOTS Alarcón, M.V. 1 - Lloret, P.G. 2 - Iglesias, D.J. 3 - Talón, M. 3 - Salguero, J. 4 1 Centro de Investigación Finca La Orden. Junta de Extremadura 2 Biología Celular. Universidad de Extremadura 3 Genómica y Poscosecha. IVIA 4 Universidad de Extremadura P - Posters Ethylene is involved in the regulation of root growth, particularly in roots growing under mechanical impedance or other stresses. The increase of ethylene production has been previously related to reductions of root length and induction of radial growth (observed as swelling in root tips). In this work, we show the effect of ACC treatments upon ethylene production compared with those on root elongation and radial growth in maize roots. The presented results demonstrate that ACC treatments increase ethylene production and vary with the concentration of ACC applied. The ethylene antagonist silver thiosulphate (STS) does not modify the increased ethylene production in response to ACC treatment. Moreover, the raise in ethylene level inhibited root elongation and increased radial expansion (swelling) as ACC concentration was increased. STS completely reversed the effects of increased ethylene levels upon the elongation and swelling without affecting the ethylene production. However, the root elongation and the radial expansion showed different sensitivity to increase in ethylene levels. Low ACC concentrations (1 μM), which significantly augmented ethylene levels, inhibited elongation but did not affect radial growth. Taken together, the results showed that root elongation is more sensitive than transversal expansion in response to increased ethylene. Financed: 2PRI01B009 Junta de Extremadura, Spain. P06-003: MTNAC969, AN ENVIRONMENTAL RESPON- SIVE TRANSCRIPTION FACTOR REGULATING MEDI- CAGO TRUNCATULA ROOT ARCHITECTURE de Zélicourt, A. 1 * - Zahaf, O. 1 - Plet, J. 1 - Diet, A. 1 - Marcel, F. 2 - Crespi, M 1 - Frugier, F. 1 - Gruber, V. 1 1 ISV CNRS 2 URGV *Corresponding author e-mail: dezelicourt@isv.cnrs-gif.fr Legumes, due to their capacity to establish symbiotic associations, are able to grow in nitrogen poor soils and are major crops worldwide. Transcription factors (TF) are able to integrate environmental and endogenous cues to control root architecture. As soil salinity is a major abiotic stress affecting crop yield, we developed transcriptomic approaches in the Medicago truncatula model to search for regulatory genes linked to salt response in roots. Forty-six salt regulated TFs were identified, three of them belonging to the NAC transcription factor family: MtNAC969, 1081 and 1126,. These TFs are specifically induced in response to salt stress in roots when compared to other abiotic stresses such as mannitol, cold or heat. The three NACs were overexpressed in M. truncatula roots and only de-regulation of MtNAC969 yield a root phenotype. This TF is closely related to AtNAP, involved in Arabidopsis leaf senescence. Overexpression of MtNAC969 reduces root growth and lateral root formation whereas symbiotic nodules showed an accelerated senescence. In addition, RNAi against MtNAC969 led to an increased root growth under salt stress, a higher number of lateral roots and a reduction of their nodulation capacity. MtNAC969 could be a new TF involved in the regulation of legume root architecture in presence of symbiotic bacteria or an abiotic stress. P06-004: POLAR IAA TRANSPORT DURING ARABIDOP- SIS ROOT GRAVITROPISM: QUANTITATIVE ANALY- SIS WITH CYTOCHEMISTRY AND GC/MS Pozhvanov, G.* - Medvedev, S. Saint-Petersburg State University, Faculty of Biology, dept. of Plant Biology and Physiology *Corresponding author e-mail: pozhvanov@gmail.com Process of polar auxin transport and its level are of great interest in cell biology. IAA accumulation in root inhibits cell elongation and thus regulates growth direction in response to gravity. Our study extends the existing methods for measuring the content of IAA through the use of cytochemistry with GC/MS. Arabidopsis DR5::GUS transformants were used. Plants were grown on a medium with different IAA concentrations for calibration and then stained with X-Gluc according to a standard protocol. Auxin content was estimated indirectly by computer analysis of stained roots digital microphotographs and matched to direct measurement of total IAA content in root 1cm sections with GC/MS, SIM version of metabolomic analysis. One 6 days old DR5::GUS seedling of Arabidopsis contained 175.6 pg IAA per g of dry mass. We also examined the IAA content in situ not only in single plant but also in different organs and specifically in gravistimulated roots. Auxin content in the bottom side of roots (30÷35 fMole/px) was 2-3 times larger than in the upper side (10÷15 fMole/px). We studied the interconnection between IAA lateral transport and cytokinin content in roots in both DR5::GUS and ARR5::GUS seedlings. Auxin content in seedlings grown on medium with BAP 10 -8 to 10 -5 M was not correlated with BAP treatment. Pos- P
FESPB 2010 - XVII Congress of the Federation of European Societies of Plant Biology sible auxin and cytokinin interactions during root gravitropism are discussed. Project was supported with RFBR Grant No. 08-04-00566a, St.-Petersburg Government Grant for Young Researchers No. 2.6/22-04/004. P06-005: THE ROLE OF APL AS A TRANSCRIPTIONAL REGULATOR IN SPECIFYING VASCULAR TISSUE IDENTITY Lichtenberger, R.* - Satu Lehesranta - Ove Lindgren - Sari Tähtiharju - Ykä Helariutta University of Helsinki *Corresponding author e-mail:raffael.lichtenberger@helsinki.fi The vascular system of higher plants confers efficient conduction and provides mechanical support. It consists of two kinds of conducting tissues, xylem and phloem. Phloem transports the products of photosynthesis and provides paths for translocation of proteins and mRNAs involved in plant growth and development. Although there are some reports of gene expression characteristic to phloem, the molecular basis of phloem development is still largely unknown. The APL transcription factor (Altered Phloem Development) was identified as the first gene specifying vascular tissue identity. Based on cell sorting coupled with genome-wide microarray analysis, we have been able to uncover phloem abundant regulatory genes dependent on APL. The results indicate that APL is a key node for transcriptional activation of gene expression characteristic to phloem development and for transcriptional repression of gene expression characteristic to xylem development. We are currently studying the possible functions of the identified genes in phloem development. P06-006: MIR390, TAS3 TA-SIRNAS AND THEIR ARF TARGETS DEFINE AN AUTO-REGULATORY NET- WORK QUANTITATIVELY CONTROLLING LATERAL ROOT GROWTH Marin, E. 1 * - Jouannet, V. 2 - Herz, A. 3 - Lokerse, A.S. 4 - Weijers, D. 4 - Vaucheret, H. 5 - Nussaume, L. 3 - Crespi, M. 2 - Maizel, A. 2 1 (CEA) 2 Institut des Sciences du Végétal 3 Laboratoire de Biologie du Développement des Plantes, SBV- ME, IBEB, DSV, CEA, CNRS, Université Aix Marseille 4 Laboratory of Biochemistry, Wageningen University 5 Laboratoire de Biologie Cellulaire, Institut Jean-Pierre Bourgin *Corresponding author e-mail: elena.marin@cea.fr Plants adapt to environmental conditions by forming new organs in response to morphogenetic signals. Lateral roots branch from the main root in response to local auxin maxima. How a local auxin maximum translates to a robust pattern of gene activation ensuring the proper growth of the newly formed lateral root is not known. Here we demonstrate that miR390, TAS3-derived tasiRNAs (trans-acting siRNAs) and ARFs form an auxin-responsive regulatory network controlling lateral root growth. Spatial expression analysis using reporter gene fusions, ta-si/miRNA sensors and mutant analysis, showed that miR390 is specifically expressed at the sites of lateral root initiation where it triggers the biogenesis of trans-acting siRNAs. These ta-siRNAs inhibit ARF2, ARF3 and ARF4, thus releasing repression of lateral root growth. In addition, ARF2, ARF3 and ARF4 control auxin-induced miR390 accumulation. Positive and negative feedback regulation of miR390 by ARF2, ARF3 and ARF4 thus ensures the proper definition of the miR390 expression pattern and maintains ARF expression in a concentration range optimal for controlling the timing of lateral root growth, a function similar to its activity during leaf development. These results also show how small regulatory RNAs integrate with auxin signalling to quantitatively control organ growth during development. P06-007: THE INHIBITION OF PRIMARY ROOT ELON- GATION UNDER LOW BORON SUPPLY COULD BE ME- DIATED BY HORMONES IN ARABIDOPSIS SEEDLINGS Martín-Rejano, E.M. - Camacho-Cristóbal, J.J. - Herrera-Rodríguez, M.B. - Rexach, J. - Navarro-Gochicoa, M.T. - González- Fontes, A. Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, E-41013, Sevilla, Spain *Corresponding author e-mail: emmarrej@upo.es Soil nutrients are critical elements for plant growth and productivity. Thus, in response to the bioavailability of nutrients in soils, plants have evolved various adaptive mechanisms among which the plastic development of the root system is of crucial importance. In this work we study in detail the temporal responses of the Arabidopsis root architecture to low boron (B) supply. For this purpose Arabidopsis seedlings were grown in 10 μM B during 5 days and then transferred to a low B medium (0.4 mM) or control medium (10 mM) for a 4-day period. Neither the length nor the number of lateral roots were affected by B availability during the 4 days of experiment; however, plants grown in the low B conditions had a reduced primary root (PR) length when compared to control plants from day 1 onwards. This is a very interesting result since lateral root growth should also be inhibited by low B supply if the primary effect of B was only on cell elongation (i.e. a consequence of the structural role of B in the cell wall). B availability also affected the number and elongation of roots hairs in the PR; thus, low B supply induced root hair proliferation and elongation. Furthermore, by using chemicals that alter hormone metabolism or signalling and several suitable mutants, we provide evidence showing that hormones could play a key role in the root architectural changes caused by low B availability. Research supported by BFU2009-08397 and Junta de Andalucía CVI-4721 and BIO-266, Spain P06-008: TOMATO MORPHOLOGICAL AND ANATO- MICAL ROOT TRAITS IN RELATION WITH PLANT WATER UPTAKE Romero Aranda, M. 1 * - Jurado-Lavado, O. 2 - Fernández-Muñoz, R. 2 1 Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Expe 2 Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA) *Corresponding author e-mail: rromero@eelm.csic.es Limited work has been performed to explore the potential for genetic improvement of tomato roots in relation to water uptake. The main goal of this study was to establish possible relationships between morphological or anatomical root characters and plant water uptake. We examined root traits in two tomato species (wild Solanum pimpinellifolium acc. TO-937 and domesticated Solanum lycopersicum cv. Moneymaker) differing in plant water use. The study was developed in a growth chamber in hydroponically cultivated plants which allowed assessing plant water uptake. Key root traits for water uptake, including root length and number of root tips were identify. Root anatomical traits, including root diameter, thickness of the cortex, number of xylem poles, number of metaxylem vessels and root and shoot biomass were also determined. In a period of 21 days, the cumulative plant water consumptions of TO- 937 and Moneymaker were 1368±419 and 3209±696 ml/ plant, respectively. Shoot dry mass determined on Moneymaker was threefold that of TO-937 but root to shoot ratio were 0.17±0.03 and 0.27±0.07 for Moneymakeer and TO-937, respectively. Plant water uptake and biomass production are discussed in relation with root development, root morphological traits and root internal anatomy.
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: FESPB 2010 - XVII Congress of the F
Page 105: FESPB 2010 - XVII Congress of the F
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
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

Create successful ePaper yourself

Delete template?

Save as template?