云南元江普通野生稻中Pi-ta和Pib同源基因的克隆和分析

用高保真PCR技术从云南元江普通野生稻中克隆了抗稻瘟病Pi-ta同源基因的编码区及Pib基因的部分同源序列。Pi-ta同源基因的编码区序列与报道的栽培稻有99.7%的同源性。根据前人的结果,从元江普通野生稻的Pi-ta基因推导的氨基酸序列中918位点为丝氨酸,属于Pi-ta~-等位基因,不能对含有AVRPita基因的稻瘟病菌产生抗性。与Pi-ta基因相比,元江普通野生稻中的Pib同源基因第一外显子与栽培稻的相应序列间存在较大差异,其中有一段87 bp的DNA序列缺失,而且不能按正常的Pib基因序列的阅读框进行翻译。因此认为,元江普通野生稻不具有基于Pi-ta和Pib基因的抗稻瘟病遗传基础。

Cloning and Analysis of Pi-ta and Pib Gene Homologues from Yunnan Yuanjiang Type of Common Wild Rice (Oryza rufipogon Griff)

The coding region of Pi-ta gene and Pib gene homologues from Yunnan Yuanjing type of common wild rice(Oryza rufipogon)had cloned and sequenced by high fidelity PCR.The cloned DNA sequence of Pi- ta gene from Yuanjiang type of common wild rice has 99.7% identity with that of cultivated rice(Oryza sativa). There was serine at the position 918 within the deduced PITA amino acid sequence.So,according to the previous study,Yuanjing type of common wild rice may contain a Pi-ta~- allele that can not cause disease resistance response with rice blast pathogens in which contain AVRPita gene.Contrary to the Pi-ta gene,the cloned Pib gene exon I DNA sequence from Yuanjiang type of common wild rice has only 93.9% identity with that of the reported O.sativa.There was 87 bp DNA sequence deletion within the cloned Pib gene exon I from Yuanjiang type of common wild rice,compared to that of the cultivated rice.And the cloned Pib gene sequence cannot be translated into the corresponding PIB amino acid sequence.So,Yuanjiang type of common wild rice may lack the Pi-ta and Pib gene based rice blast resistance abilities.