Natural variation of rice blast resistant gene Pi-ta in Oryza species

Authors: WANG, XUEYAN - UNIVERSITY OF AR RREC; Jia, Yulin; SHU, QINGYAO - ZHEJIAN UNIVERSITY, CHINA

Submitted to: American Phytopathological Society
Publication Type: Proceedings
Publication Acceptance Date: 4/15/2007
Publication Date: 7/29/2007
Citation: Wang, X., Jia, Y., Shu, Q. 2007. Natural variation of rice blast resistant gene Pi-ta in Oryza species. American Phytopathological Society Meeting, July 28-August 1, 2007, San Diego, CA. 97:S120.

Interpretive Summary:

Technical Abstract: The Pi-ta gene in rice is a putative NBS type cytoplasmic receptor conferring resistance to races of Magnaporthe oryzae in a gene-for-gene manner. A Functional Nucleotide Polymorphism (FNP) change resulting in an amino acid substitution of Alanine to Serine at position 918 (nucleotide G to T at position 6640) determines the resistance specificity. To study the origin and evolution of Pi-ta, the structure and function of Pi-ta in 219 accessions selected from a USDA collection of Oryza sativa, its wild relatives including O. rufipogon, O. nivara, O. barthii, O. glaberrima, O. officinalis, and U.S. red rice collections were analyzed. Highly similar Pi-ta orthologs with several insertion/deletion (indels) and Single Nucleotide Polymorphisms (SNPs) have been found in sequenced accessions. Thus far, 15 haplotypes of Pi-ta were identified based on DNA sequences, and 13 haplotypes were identified based on amino acid sequences in 46 selected accessions. Overall, more polymorphic nucleotides existed in the intron region than in the exon regions. Moreover, a SNP of nucleotide G at position 4234 and the indel of GCC at positions 4426 to 4428 in the intron region were found to correlate with the FNP of G at position 6640. These SNPs, indels and FNP should be useful for marker assisted Pi-ta incorporation.