Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/3/2004
Publication Date: 7/30/2004
Citation: Jia, Y., Singh, P., Winston, E.M., Wamishe, Y., Correll, J., Valent, B. 2004. Molecular evolution of rice Pi-ta gene and fungal Magnaporthe grisea AVR-Pita gene. American Phytopathological Society Annual Meeting. Phytopathology. 94(6):47.
Technical Abstract: Rapid changes in Magnaporthe grisea avirulence genes often defeat resistance gene mediated resistance. The Pi-ta resistance gene in rice is effective in preventing infections by Magnaporthe grisea isolates containing the corresponding avirulence gene AVR-Pita. Pi-ta is a putative cytoplasmic nucleotide binding site receptor that appears to interact with AVR-Pita directly in triggering the resistance. AVR-Pita is a predicted metalloprotease that may play roles in pathogenicity and fitness. In the Southern US, Pi-ta has been effective since its release in the 1980s. Fifteen AVR-Pita alleles from four MGR 586 DNA fingerprint groups A, B, C and D of the US field M. grisea isolates were sequenced. All 15 have an identical AVR-Pita amino acid sequence which has six amino acid alterations from published AVR-Pita protein. In contrast, most isolates regaining the ability to infect Pi-ta containing plants did not have an intact AVR-Pita allele. Analysis of coevolution of both Pi-ta and AVR-Pita and dual roles of AVR-Pita will be presented.