水稻抗白叶枯病基因Xa23启动子变异及功能标记  

Variation and Functional Markers of Xa23 Promoter of Rice Bacterial Blight Resistance Gene

作　　者：张丹丹 范玉龙 纪向云 夏志辉[1] Zhang Dandan;Fan Yulong;Ji Xiangyun;Xia Zhihui(Hainan Key Laboratory for Sustinablel Utilizatio of Tropical Biorsources,College of Topical Crops,Hainan University,Haikou 570228)

机构地区：[1]海南大学热带作物学院,海南省热带生物资源可持续利用重点实验室,海口570228

出　　处：《分子植物育种》2020年第21期7088-7094,共7页Molecular Plant Breeding

基　　金：海南省自然科学基金(318MS007);2019年海南省基础与应用基础研究(自然科学领域)高层次人才项目基金(2019RC095);2019年度海南省重大科技计划项目(ZDKJ201901)共同资助。

摘　　要：Xa23是广谱强效的水稻抗白叶枯病显性基因,其与等位感病基因xa23功能差异在于启动子上的被水稻白叶枯病菌无毒效应因子avrXa23能识别激活28 bp核心序列(EBEavr Xa23),开发其功能标记能够加快水稻育种进程。本研究检测43份国外野生稻、7份代表性常规稻的Xa23启动子,利用生物信息软件Vector NTI对启动子上游200 bp序列进行分析。结果表明,只有9份普通野生稻,2份常规稻能扩增出启动子上游约200 bp序列,检出率只有22.0%,说明Xa23不广泛存在于水稻中;进一步的序列分析显示,EBEavr Xa23序列存在丰富的变异,其等位序列至少存在7种单倍型,但EBEavr Xa23只存在水稻CBB23中。最后,依据EBEavr Xa23序列开发了Xa23显性功能标记,经验证该标记能明确区分水稻是否携Xa23基因。本研究将有助于进一步研究Xa23进化机制及分子标记辅助选择育种。Xa23 is a dominant gene with broad spectrum and strong resistance to bacterial blight of rice. The functional difference between Xa23 and the allele susceptible gene xa23 lies in the 28 bp core sequence on the promoter that is recognized and activated by the avirulent effector avrXa23 of Xanthomonas oryzae pv. Oryzae(EBEavr Xa23) and development of Xa23 functional markers can speed up the process of rice breeding. In this study,the Xa23 promoters of 43 wild rice and 7 representative conventional rice were tested, and the 200 bp sequence upstream of the promoter was analyzed using Vector NTI. The results showed that only 9 common wild rice and 2 conventional rice could amplify about 200 bp sequence upstream of promoter, and the detection rate was only22.0%, indicating that Xa23 was not widespread in rice. Further sequence analysis showed that there were abundant variations in the sequence of EBEavr Xa23, with at least seven haplotypes in its allele sequence, but EBEavr Xa23 only exists in rice CBB23. Finally, the Xa23 dominant functional marker was developed based on the sequence of EBEavr Xa23. It was verified that the marker could clearly distinguish whether there was Xa23 gene in rice. This study will be helpful to further study the evolution mechanism of Xa23 and molecular mark assisted breeding.

关 键 词：水稻白叶枯病 Xa23启动子 序列分析 EBEavrXa23 分子标记 

分 类 号：S435.111.47[农业科学—农业昆虫与害虫防治]