|Valent, Barbara - KSU|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 4, 2005
Publication Date: January 5, 2009
Citation: Jia, Y., Valent, B. 2009. Molecular aspects of rice blast disease resistance: Insights from structural and functional analysis of the Pi-ta and AVR-Pita gene pair. In: Datta, S., editor. Rice Improvements in the Genomic Era. Boca Raton, FL: CRC Press, Taylor & Francis Group. p. 207-236. Technical Abstract: Improved resistance to blast disease can benefit from molecular characterization of major blast R genes. The Pi-ta gene in rice prevents the infections of races of the rice blast fungus Magnaporthe grisea containing the corresponding avirulence AVR-Pita gene. Pi-ta, a single copy gene encodes a predicted cytoplasm receptor that is located near the centromere region of the rice chromosome 12. AVR-Pita in M. grisea encodes a predicted metalloprotease and is located near the telomere of the fungal chromosome 3. We found that Pi-ta is effective in preventing the blast disease in the US rice fields. Analysis of natural alleles of Pi-ta from rice germplasm identified one Pi-ta allele conferring resistance and three pi-ta alleles conferring susceptibility. These DNA sequence variation at the Pi-ta locus facilitated us in developing unique DNA primers for the resistant Pi-ta and susceptible Pi-ta alleles. These primers have been successfully used to develop both dominant and codominant markers from the Pi-ta gene itself for marker-assisted selection in the US. Long term, understanding how the Pi-ta protein successfully perceives the pathogen signal, and triggers an effective resistance would lead new knowledge to control the blast disease.