关键词: DNA多态性, 基因克隆, Pi-ta+ 等位基因, 景洪直立型普通野生稻

Abstract:

A 4 672 bp DNA sequence including the whole coding region and partial non-coding region of rice blast
resistance gene Pi-ta⁺ has been cloned from Jinghong erect type of common wild rice (Oryza rufipogon Griff) in Yunnan by polymerase chain reaction method. The coding region shares 99.86% and 98.78% identity with the corresponding regions of the reported cultivated rice Yashiro-mochi and Yuanjiang type of common wild rice respectively. There are 4 nucleotides difference in the coding region and 6 in intron of the cloned Pi-ta⁺ gene,compared with Pi-ta from Yashiro-mochi. Pi-ta⁺ gene in Jinghong erect type of common wild rice has been proved to be a rare existing Pi-ta⁺ allele, because there was a alanine rather than a serine at the position 918 within the predicted amino acid sequence of PITA. Pi-ta⁺ allele can cause disease resistance response to rice blast pathogens in plant cells. Differences in DNA sequence, deduced amino acid se-quence and antibacterial spectrum may make the Pi-ta⁺ allele new resistant characteristics. Finding and cloning of Pi-ta⁺ allele from Jinghong erect type of common wild rice in Yunnan provides a basement for further utilization of the wild rice resources.