Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Functional Analysis
            

TOWARDS A BETTER UNDERSTANDING OF BERRY QUALITY AND POWDERY MILDEW RESISTANCE IN GRAPEVINE: GENETIC DETERMINISM AND PATHWAYS

¹ UMR Agro-M/INRA/UMI Sciences pour l'Oenologie, 2, Place Pierre Viala 34060 Montpellier Cedex 01

² UMR Agro-M/CIRAD/INRA/IRD Diversite et Genomes des Plantes Cultivees, 2, Place Pierre Viala 34060 Montpellier Cedex 01

³ MR Agro-M/CIRAD/INRA/IRD Biologie du Developpement des Plantes Perennes Cultivees, 2, Place Pierre Viala 34060 Montpellier Cedex 01

⁴ UMR Agro-M/CIRAD/INRA Biologie et genetique des interactions plante/parasite, 2, Place Pierre Viala 34060 Montpellier Cedex 01

Main objectives of the program are to identify genes involved in berry development and maturation, resistance to pathogens and to dissect the genetic determinism of both powdery mildew resistance and berry quality. The program will integrate 3 complementary approaches:Genetic mapping and QTL analysis, transcriptome and proteome analysis and functional studies and promoters analysis A genetic map, based on microsatellites is in progress on a cross between Syrah and Grenache. A gene map will also be developed, using genes identified by the transcriptome analysis. QTL linked to traits correlated to berry quality will be searched. First results should be available in three years. Other crosses between Syrah, Grenache and an interspecific hybrid partially resistant to powdery mildew will also be analyzed, and QTLs for powdery mildew resistance will be searched. In order to use more promising resistance source, considering resistance efficiency and durability, an analysis of Uncinula necator populations is carried on to evaluate potential fungus adaptation to resistant germplasm. Sequencing of 15000 Est is planed before the end of 2002, 1020 non redundant EST from green, veraison, and ripe berries being presently classified in functional categories. Electronic northern blot and SSH confirms the overexpression of GRIPs during ripening. Microarray technology and 2D gel electrophoresis, coupled with MALDI-TOF analysis, allow to validate expression data at the transcriptome and proteome levels. Studies on the regulation of gene expression are being developed to determine factors and mechanisms that control transcription in grape berry during development. In particular, regulatory sequences present in promoter of ripening-related genes are being investigated by transient expression using biolistic on V. vinifera suspension cells. To complete this aspect, sens and antisense strategies are developed to evaluate physiological importance of selected genes.