ARS | Publication request: MOLECULAR CO-EVOLUTION OF THE RICE PI-TA RESISTANCE GENE AND MAGNAPORTHE ORYZAE AVIRULENCE GENE AVR-PITA

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: December 15, 2005
Publication Date: November 1, 2006
Citation: Jia, Y., Zhou, E., Winston, E., Singh, P., Correll, J., Lee, F.N., Valent, B. 2006. Molecular co-evolution of the rice Pi-ta resistance gene and Magnaporthe oryzae avirulence gene AVR-pita. In: Sanchez, F., Quinto, C., Lopex-Lava, I.M., Geiger,, D., editors. Biology of Plant-Microbe Interactions, Volumn 5. p. 325-339.

Technical Abstract: The Pi-ta gene in rice confers resistance to races of Magnaporthe oryzae containing the corresponding avirulence gene AVR-Pita. Pi-ta encodes a putative cytoplasmic protein with nucleotide binding sites and a leucine rich repeat. AVR-Pita encodes a metalloprotease, and its processed form AVR-Pita 176 interacts directly with the Pi-ta protein to trigger complete resistance to M. oryzae races containing the corresponding avirulence gene AVR-Pita. The population biology of both Pi-ta and AVR-Pita was studied. Rice cultivars with either one resistant Pi-ta all or one of three susceptible pi-ta alleles were discovered from a survey of rice germplasm. Nucleotide substitutions occurred at conserved positions of the various Pi-ta/pi-ta haplotypes, this feature allows the development of DNA markers from cloned genes for marker-assisted selection. In contrast, sequence analysis of a collection of M. oryzae isolates revealed highly conserved AVR-Pita protein, and a transposon Pot3 was found to insert into the conserved functional motif of the AVR-Pita protein in a virulent isolate collected from a commercial rice field. Progress in studying the Pi-ta and AVR-Pita interacting genes is reported.