ARS | Publication request: TRANSLATIONAL GENOMICS: A CASE STUDY OF RICE PI-TA RESISTANCE GENE

Submitted to: Plant Molecular Biology International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2005
Publication Date: October 27, 2005
Citation: Jia, Y., Zhou, E., Winston, E., Singh, P., Wang, Z., Correll, J., Lee, F., Jia, M.H. 2005. Translational genomics: a case study of rice Pi-ta resistance gene. In: Proceedings of International Conference on Plant Molecular Breeding, October 27-30, 2005. p. 3.

Technical Abstract: Blast disease is one of the most destructive rice diseases worldwide. The Pi-ta resistance gene is one of those R genes characterized at the molecular level. 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 the race of Magnaporthe grisea containing the corresponding avirulence gene AVR-Pita. One resistant Pi-ta and three susceptible pi-ta alleles were identified from rice germplasm. An alignment of DNA sequences of these Pi-ta haplotypes identified several conserved nucleotide substitutions, and these nucleotide differences were used to develop PCR based markers for stacking the Pi-ta gene into advanced rice breeding lines by marker-assisted selection (MAS). Similarly, results of structural and functional studies of avr-pita alleles in US M. grisea pathotypes suggests that transposition, insertion and deletion of DNA sequences at the AVR-Pita locus may be responsible for the instability of AVR-Pita, and thus it is a likely mechanism to defeat the resistance mediated by Pi-ta. A combination of genetic and biochemical approaches has been undertaken to understand the coevolution of a plant R gene and a corresponding pathogen AVR gene. Recent progress in developing the molecular methods for rice breeding and crop protection will be presented.