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United States Department of Agriculture

Agricultural Research Service


item Jia, Yulin
item Crowley, Eugenia
item Singh, Pratibha
item Zhou, Erxun
item Wamishe, Yeshi
item Jia, Melissa
item Correll, James

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2004
Publication Date: 11/15/2004
Citation: Jia, Y., Winston, E.M., Singh, P., Zhou, E., Wamishe, Y., Jia, M.H., Correll, J. 2004. Molecular mechanisms of durable rice blast resistance [abstract]. In: Proceedings, 2nd International Rice Functional Genomics Conference, Tucson, Arizona. Abstract p. 72.

Interpretive Summary:

Technical Abstract: Durable resistance to the blast pathogen, Magnaporthe grisea, can be achieved by deploying a resistance gene that recognizes a virulence factor that is essential for the pathogen to cause disease. The Pi-ta gene in rice is effective in preventing the infection of M. grisea races containing the corresponding avirulence gene AVR-Pita. Pi-ta is a single copy gene located at the centromere of chromosome 12. Pi-ta encodes a predicted cytoplasmic protein with a centrally located nucleotide-binding site and a leucine rich domain at its carboxyl terminus. AVR-Pita is a metalloprotease located near the teleometric region of chromosome 3 of M. grisea. Pi-ta appears to recognize AVR-Pita inside the host cell triggering effective defense response. A survey of rice germplasm (in different rice production regions) has identified one resistant (Pi-ta) haplotype and three susceptible pi-ta haplotypes. Pi-ta confers resistance to the major US M. grisea pathotypes; the polymorphic regions of Pi-ta that distinguish resistant and susceptible alleles of Pi-ta were successfully used for the development of dominant and codominant markers for marker assisted Pi-ta incorporation. Survey of the pathogen population in the USA indicates that the deletion of the AVR-Pita allele in some "race-shift" isolates of M. grisea can defeat protection provided by Pi-ta. Race-shift isolates have been selected and recovered from the field. Whether such isolates can prevail and cause economic losses depends on the role of AVR-Pita in both pathogenesis and pathogen fitness in the environment. Progress on the development of molecular strategies to control rice blast disease will be presented.

Last Modified: 10/19/2017
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