Plant & Animal Genomes XIII Conference

January 15-19, 2005
Town & Country Convention Center
San Diego, CA

Construction Of BAC And Full-Length cDNA Libraries For Genomic Analysis Of The Wheat Stripe Rust Pathogen (Puccinia Striiformis f. sp. tritici)

Paul Ling , Xianming Chen , Dat Q Le , Kimberly G Campbell

  USDA-ARS, Wheat Genetics, Quality, Physiology, and Disease Research Unit, Pullman, WA 99164-6430

Puccinia striiformis Westend. f. sp. tritici causes stripe rust, one of the most destructive diseases of wheat worldwide. The genomic information of the fungus is currently unavailable. To determine sequence and genomic structures of the fungus and identify genes involved in its pathogenicity and biological development, we constructed a HindIII BAC library and a full-length cDNA library using urediniospores of race PST-78 of P. striiformis f. sp. tritici that has been predominant throughout North America. The BAC library consists of 22,272 clones with an average insert size of 60kb, and was estimated to have at least 10X coverage of the genome. A method using small amount of urediniospores to generate sufficient amount of HMW DNA was developed. The BAC clones will be used to generate whole genome physical map for the fungus. The full-length cDNA library consists of 42,240 clones, and 99% of the clones reached full-length with the average cDNA insert of 1.5kb. The functional analysis was initiated by sequencing 200 randomly selected cDNA clones. The sequences were compared with the accessions in the fungal gene database of the GenBank and categorized according to their putative functions. Genes like beta-tubulin, deacetylase, glyoxyloxidase, hydrophobin and mitigen-activated protein kinase were identified. These genetic resources and current results will serve as genomic platforms and starting points for the further studies of the P. striiformis genome.