Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/16/2008
Publication Date: 8/24/2008
Citation: Chen, X., Coram, T., Settles, M.L., Wang, M.N. 2008. Comparison of wheat defense genes in race-specific and non-race specific resistances to stripe rust. J. Plant Pathol. 90(S2):215.
Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important wheat disease worldwide. Sustainable control of the disease relies on durable type of resistance and appropriate use of effective non-durable type of resistance. All-stage (AS) resistance, which provides complete protection and is qualitatively inherited, is usually race-specific and not durable, while high-temperature adult-plant (HTAP) resistance, which is partial and quantitatively inherited, is non-race specific and durable. To understanding molecular mechanisms of these two types of resistance, the wheat GeneChip was used to profile the transcriptional changes occurring in wheat lines with or without the Yr5 gene for AS resistance and Yr39 for HTAP resistance after inoculation with the stripe rust pathogen. The peak expressions of most Yr5-regulated genes occurred at 24 h while significance increase in expression level for most Yr39-regulated genes did not occur until 48 h after inoculation. A total of 64 transcripts were identified to be up-regulated by Yr5 while 99 transcripts were induced during the Yr39-mediated HTAP resistance, indicating that HTAP resistance has a broader molecular basis than AS resistance. Of these genes, 14 were common in the two types of resistance and 11 of them were identified as hypersensitive-response genes, which might be related to hypersensitive response observed in both types of resistance. Six of the Yr39-regulated genes were R genes while none of the Yr5-regulated genes are R genes. Race-specific AS resistance included more PR protein and hypersensitive response transcripts, while overall HTAP resistance involved a greater diversity of defense-related pathways.