Construction and characterization of a full-length cDNA library for the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici)
1 US Department of Agriculture, Agricultural Research Service, Wheat Genetic, Quality, Physiology and Disease Research Unit, Pullman, WA 99164-6430, USA
2 Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA
3 College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
4 Department of Soil and Crop Sciences, Washington State University, Pullman, WA 99164-6420, USA
BMC Genomics 2007, 8:145 doi:10.1186/1471-2164-8-145Published: 4 June 2007
Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi.
A full-length cDNA library, consisting of 42,240 clones with an average cDNA insert of 1.9 kb, was constructed using urediniospores of race PST-78 of P. striiformis f. sp. tritici. From 196 sequenced cDNA clones, we determined functions of 73 clones (37.2%). In addition, 36 clones (18.4%) had significant homology to hypothetical proteins, 37 clones (18.9%) had some homology to genes in other fungi, and the remaining 50 clones (25.5%) did not produce any hits. From the 73 clones with functions, we identified 51 different genes encoding protein products that are involved in amino acid metabolism, cell defense, cell cycle, cell signaling, cell structure and growth, energy cycle, lipid and nucleotide metabolism, protein modification, ribosomal protein complex, sugar metabolism, transcription factor, transport metabolism, and virulence/infection.
The full-length cDNA library is useful in identifying functional genes of P. striiformis.