W075 Genome-wide transcript profiling of barley rar3 in response to powdery mildew

Date: Saturday, January 14, 2012
Time: 2:30 PM
Room: San Diego
Roger Wise , USDA-ARS / Iowa State University, Ames, IA
Priyanka Surana , Bioinformatics and Computational Biology Graduate Program, Iowa State University, Ames, IA
Greg Fuerst , USDA/ARS, Iowa State University, Ames, IA
Dan Nettleton , Department of Statistics, Iowa State University, Ames, IA
Lin Wang , Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY
Thomas P. Brutnell , Boyce Thompson Institute, Cornell University
Genes encoding early signaling events in pathogen defense often are identified only by their phenotype.  Such genes involved in barley-powdery mildew interactions include Mla, specifying race-specific resistance; Rar1 (Required for Mla12-specified resistance1), and Rom1 (Restoration of Mla-specified resistance1).  The RAR1-SGT1-HSP90 complex appears to function as chaperone in MLA-specified resistance, however, much remains to be discovered regarding the precise mechanisms of plant immunity.  Genetic analyses of fast-neutron mutants derived from CI 16151 (Mla6) uncovered a novel locus, designated Rar3 (Required for Mla6-specified resistance3).  Rar3 is independent of Mla6 and Rar1, and rar3 mutants are susceptible to Blumeria graminis f. sp. hordei (Bgh) isolate 5874 (AVRa6), whereas, wild-type progenitor plants are resistant.  Seven-day old seedlings (PO:0007094) from the rar3 mutant and wild-type progenitor were inoculated with Bgh 5874, harvested at 16 and 32 HAI, and subjected to both Barley1 GeneChip and RNA-seq analyses.  A randomized block design with two independent biological replications was used to obtain expression measurements.  The resulting data sets are being used for two purposes; 1) transcript-based isolation of the gene(s) responsible for the rar3 phenotype, and 2) an assessment of rar3-mediated transcriptome reprogramming in both compatible and incompatible interactions in response to challenge with the biotrophic pathogen, Bgh 5874. Research supported in part by NSF Plant Genome grant #0922746.