Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/31/2003
Publication Date: 1/10/2004
Citation: Jia, Y., Wang, Z., Singh, P., Redus, M., Fjellstrom, R.G., Johnson, V., Correll, J., Lee, F., Rutger, J.N. 2004. Rice Pi-ta gene confers resistance to the major pathotypes of the rice blast fungus in the U.S. [abstract]. Annual International Plant & Animal Genome Conference. Abstract P293, p. 145. Interpretive Summary:
Technical Abstract: The Pi-ta gene in rice prevents the infection of Magnaporthe grisea isolates containing the avirulence AVR-Pita gene. Pi-ta encodes a putative cytoplasmic receptor that appears to bind to a predicted processed AVR-Pita to elicit a defense response. The presence of the Pi-ta gene was detected in 13 rice cultivars that reportedly contain Pi-ta. All Pi-ta containing cultivars were resistant to both major pathotypes IB-49 and IC-17 of M. grisea. The inheritance of resistance to IC-17 was further investigated using a marker for the resistant Pi-ta allele in an F2 population of 1345 progeny of the cross with a Pi-ta containing rice cultivar. Resistance to IC-17 was conferred by a single dominant gene, and Pi-ta was not detected in susceptible individuals. Another F2 population of 377 individuals of a reciprocal cross was used to verify the conclusion that resistance to IC-17 was conferred by a single dominant gene. In this cross, individuals resistant to IC-17 were also resistant to IB-49. The presence of Pi-ta and resistant to IB-49 was also correlated with additional crosses involving another Pi-ta containing rice culitvar. A pair of primers that specifically amplifies a susceptible pi-ta allele was developed to verify the absence of the dominant Pi-ta gene. These data suggest that Pi-ta is responsible for resistance to IB-49 and IC-17. The correlation of Pi-ta with resistance to both M. grisea pathotypes suggesting they contain functional AVR-Pita genes. Progress on developing molecular markers to facilitate the incorporation of Pi-ta into improved rice germplasm will be described.