Plant & Animal Genomes XIV Conference Plant & Animal Genomes XIV ConferenceJanuary 14-18, 2006
Town & Country Convention Center
San Diego, CA
Dimitar Douchkov , Wubei Dong , Uwe Zierold , Patrick Schweizer
Barley is one of the most important feed and food crops worldwide. Despite its agronomic importance and excellent, available genetic resources, tools for genome-wide analysis of barley have only recently been initiated and include high-resolution genetic maps, physical gene mapping, highly efficient protocols for genetic transformation, insertion mutagenesis, TILLING platforms, a large EST collection as well as gene arrays for expression profiling. We have contributed to extending this genomics toolbox in barley by establishing 22,000 EST sequences from powdery mildew-attacked barley epidermis, a 10K cDNA array as well as a high-throughput RNAi system for assessing gene function in attacked barley epidermal cells. The RNAi system for transient-induced gene silencing (TIGS) based on biolistic transgene delivery is being used to study the function of approximately 800 barley candidate genes including 693 up-regulated genes and 101 resistance-gene analogues expressed in barley epidermis. The library of RNAi constructs was tested in TIGS screenings for breakdown of nonhost resistance against wheat powdery mildew and for modification of basal host resistance. Twelfe candidate genes out of 787 tested that caused reproducible, partial breakdown of nonhost resistance or that modified basal host resistance are being analyzed in greater detail including their possible role in mlo- and Mla-mediated as well as basal (quantitative) resistance against powdery mildew.