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Session 4 – Biotic and Abiotic Stresses KEYNOTE LECTURE S4.1- Exploiting Brachypodium distachyon biodiversity to establish sources of resistance to abiotic and biotic stress. Luis A. J. Mur 1, Joel Allaingullianme 1, Jessica Gough 1, Rasim Uman 1, Ianto Thomas 1, J. William Allwood 1, Joel V. Smith, 1 Greg Shelley 1, Andrew P. M. Routledge 1, Adina Breiman 2, Elena Benavente 3 and Pilar Calatan 4. 1 Institute of Biological, Environmental and Rural Science, Penglais Campus, Aberystwyth University 2 Dept of Plant Sciences Tel Aviv University, Tel Aviv Israel 69978 3 Department of Biotechnology, Polytechnic University of Madrid, 28040-Madrid, Spain 4 Department of Agriculture (Botany), High Polytechnic School of Huesca, University of Zaragoza, Ctra. Cuarte km 1, 22071 Huesca, Spain. lum@aber.ac.uk Abstract Brachypodium distachyon is an undomesticated model grass species which offers the possibly of elucidating the genetic bases of multigenic traits associated with abiotic stress tolerance and durable disease resistance (Mur et al. 2011). To exploit this potential we have established collections of Brachypodium distachyon and Brachypodium hybridum (formerly the 2n =30 cytotype of B. distachyon; see presentation by Catalan et al.) germplasm from Northern Spain and also via, collaboration, incorporated collections from Southern Spain, Morocco, Israel as well as accessions from Italy, France and Bulgaria. Genetic diversity within Brachypodium germplasm was assessed through polymorphism at microsatellite loci. Accession genetic diversity was related to geographical origin with distinct polymorphisms between Western and Eastern European accession and also between Brachypodium species. Biochemical variation amongst the accessions was investigated by metabolite fingerprinting using Fourier Transform Infra-Red (FT-IR) spectroscopy. Using the supervised multivariate approach – Discriminant Function Analysis (DFA) - variation in metabolites in the first emerged leaf of Brachypodium genotypes could be linked to geographical origin. Our assessments of drought tolerance focused on inbred lines developed from our collection and also the ABR1 through 7 series, USDA lines Bd21, Bd2-3, Bd3-1 as well as from the Turkish collection established by Vogel et al. (2009). A total of 118 Brachypodium genotypes have been assessed for drought tolerance and, based on estimates of relative water content and cytoplasmic membrane stability, Bd2-3 proved to be most drought susceptible and ABR5 the most tolerant. Metabolomic approaches were employed to further investigate the basis of the variation in tolerance, based on electrospray ionisation Mass Spectrometry (ESI-MS) of polar and non-polar extracts from drought and non-droughted plants. Multivariate data mining indicated that polyamine, arginine and antioxidant metabolites were all elevated in ABR5 and not Bd2-3. We are now seeking to develop mapping populations to deduce genetic traits linked to drought tolerance. Our work on responses to pathogens has focused on responses to Magnaporthe grisea - the causal agent of rice blast - and rust pathogens, primarily crown rust (Puccina coronata) and the emerging grassland pathogen, Dreschlera spp. Leafspot in the ABR1 through 7 genotypes. Events associated with local and systemic resistance to pathogens have been elucidated. Resistance to pathogens was correlated with an elevation in jasmonic acid but not salicylic acid. Inhibition of jasmonic acid biosynthesis using ursolic acid resulted in reduced local and systemic resistance. Lipoxygenase (LOX) is a key biosynthetic enzyme in the jasmonate biosynthetic pathway. Two LOX Bd21 T-DNA mutants are available within the JIC (UK) T-DNA population (BdAAA466, BdAAA615) and both exhibited reduced jasmonate accumulation on infection and compromised resistance to rice blast. These data suggest the importance of jasmonate signalling in Brachypodium and most likely, temperate cereals. References Mur LA, Allainguillaume J, Catalán P, et al. (2011) Exploiting the Brachypodium Tool Box in cereal and grass research. New Phytol. 2011 91, 334-47. Vogel JP, Tuna M, Budak H, et al. (2009). Development of SSR markers and analysis of diversity in Turkish populations of Brachypodium distachyon. BMC Plant Biology: 13:9:88 31
Session 4 – Biotic and Abiotic Stresses S4.2- Assessing the role of smallRNAs in leaf cell identity and growth reprogramming during drought stress in Brachypodium distachyon Mica, Erica 1 ; Bertolini, Edoardo 1,2; Verelst, Wim 2; Piccolo, Viviana 3; Inzé, Dirk 2; Horner, David 3 ; Pè, Mario Enrico 1 1 Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy 2 Department of Molecular Genetics, Ghent University, Technologiepark 927, 9052 Ghent, Belgium 3 Department of Biomolecular Sciences and Biotechnology, University of Milan, via Celoria 26, 20133 Milan, Italy erica.mica@sssup.it Abstract Food production is limited primarily by environmental stresses, of which drought is one of the most common. Water deficiency in fact affects both growth and development of crop plants through alterations in metabolism and gene expression. As a drought tolerant grass, Brachypodium may possess specific adaptations and tolerance mechanisms whose characterization could be useful to address drought tolerance in related crops, such as wheat and barley. The drought response is a complex trait regulated by a plethora of genetic and epigenetic networks. Here we address the role of smallRNA molecules, in particular miRNAs, in fine tuning gene expression in developing leaves under drought stress. In our soil-based assay, we subjected the reference accession Bd21 to growth-limiting, non-lethal drought stress. In this condition, we observed that drought stress has no effect on cell division rates but affects cell expansion resulting in a reduced leaf size. From two biological replicates we produced four smallRNA libraries obtained from expanding and proliferating leaf zones subjected either to drought stress or control conditions. Using nextgeneration sequencing techniques the libraries were sequenced, producing nearly 30 million reads. The bioinformatics pipeline that we developed identified conserved and species-specific miRNAs, some of which were detected for the first time in Brachypodium. Statistical analyses were applied to detect miRNAs whose expression is modulated under stress or in different developmental conditions. Our data suggest that a higher proportion of miRNAs are involved in developmental programming, while only few miRNAs are regulated under drought stress in Brachypodium. We are currently analyzing putative miRNAs targets investigating their possible involvement in leaf development both in normal and stressed conditions. Combining miRNAs and miRNA target genes analyses we expect to obtain a more complete picture of the biological function of these molecules. Keywords miRNA, smallRNA, drought, growth-reprogramming, leaf 32
Page 2 and 3: Acknowledgements: Institut National
Page 4 and 5: Contents Programme 4 Oral presentat
Page 6 and 7: Wednesday 19 th October, 2011 11:00
Page 8 and 9: Friday 21 st October, 2011 Biotic a
Page 10 and 11: ORAL COMMUNICATIONS 9
Page 12 and 13: Session 1 - Evolution and Natural V
Page 18 and 19: Session 2 - Cell Wall, Biomass and
Page 26 and 27: Session 3 - Tools and Bioengineerin
Page 34 and 35: Session 4 - Biotic and Abiotic Stre
Page 42 and 43: Session 5 - Plant Development, Meta
Page 74 and 75: S: Speakers’ abstracts P: Posters
Page 76 and 77: LIST OF PARTICIPANTS 75
Page 78 and 79: BOUCHABKE-COUSSA Oumaya INRA IJPB I
Page 80 and 81: GIRALDO Patricia E.T.S.I. Agronomos
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MARION-POLL Annie INRA IJPB Institu
Page 84 and 85:
RENAULT Hugues CNRS - IBMP Institut
Page 86:
WARD Eric Two Blades Foundation, P.
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