ARS | Publication request: Genetic and genomic dissection of resistance genes to the rice sheath blight pathogen

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 18, 2010
Publication Date: December 13, 2010
Citation: Jia, Y. 2010. Genetic and genomic dissection of resistance genes to the rice sheath blight pathogen. Plant and Animal Genome Conference. http://www.intl-pag.org/19/abstracts/P05b_PAGXIX_257.html.

Technical Abstract: Rice sheath blight disease caused by the anastomosis group AG1-IA of the fungal pathogen Rhizoctonia solani is one of the most serious rice diseases in the southern US and the world. The use of fungicides is a popular but costly method to control this disease worldwide. Genetic analysis of host resistance has allowed the identification of rice cultivars that differ in their levels of resistance. A major resistant allele qSB9-2 on chromosome 9 in the cultivar Jasmine 85 that explains 25-30% of the phenotypic variation was mapped using a highly-controlled micro-chamber inoculation method. At qSB9-2, one hundred twenty candidate genes were identified based on genome sequence. Using genome-wide DNA microarrays, serial analysis of gene expression, and sequence analysis of a suppressive subtractive hybridization library, revealed that expression of most of the candidate genes was not influenced by infection by the pathogen. However, a few of these candidate genes were found to be induced as determined by real time PCR using Jasmine 85 leaf tissue at different time points after inoculation with R. solani. In parallel, a comparative study of the rice-Magnaporthe pathosystems was also undertaken to identify genes that may be important for R. solani pathogenesis. Progress on characterization of host candidate genes, R. solani pathogenicity factors and their interactions will be presented.