Xa7, a new executor R gene that confers durable and broad-spectrum resistance to bacterial blight disease in rice  

作　　者：Xifeng Chen Pengcheng Liu Le Mei Xiaoling He Long Chen Hui Liu Shurong Shen Zhandong Ji Xixi Zheng Yuchen Zhang Zhenyu Gao Dali Zeng Qian Qian Bojun Ma 

机构地区：[1]College of Chemistry and Life Sciences,Zhejiang Normal University,Jinhua 321004,China [2]China National Rice Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310006,China

出　　处：《Plant Communications》2021年第3期68-81,共14页植物通讯（英文）

基　　金：supported by the Ministry of Agriculture and Rural Affairs of China(2016ZX08009003-001);the National Natural Science Foundation of China(32071987,31871605);the Natural Science Foundation of Zhejiang Province(LD19C130001).

摘　　要：Bacterial blight(BB)is a globally devastating rice disease caused by Xanthomonas oryzae pv.oryzae(Xoo).The use of disease resistance(R)genes in rice breeding is an effective and economical strategy for the control of this disease.Nevertheless,a majority of R genes lack durable resistance for long-term use under global warming conditions.Here,we report the isolation of a novel executor R gene,Xa7,that confers extremely durable,broad-spectrum,and heat-tolerant resistance to Xoo.The expression of Xa7 was induced by incompatible Xoo strains that secreted the transcription activator-like effector(TALE)AvrXa7 or PthXo3,which recognized effector binding elements(EBEs)in the Xa7 promoter.Furthermore,Xa7 induction was faster and stronger under high temperatures.Overexpression of Xa7 or co-transformation of Xa7 with avrXa7 triggered a hypersensitive response in plants.Constitutive expression of Xa7 activated a defense response in the absence of Xoo but inhibited the growth of transgenic rice plants.In addition,analysis of over 3000 rice varieties showed that the Xa7 locuswas found primarily in the indica and aus subgroups.A variation consisting of an 11-bp insertion and a base substitution(G to T)was found in EBEAvrXa7 in the tested varieties,resulting in a loss of Xa7 BB resistance.Through a decade of effort,we have identified an important BB resistance gene and characterized its distinctive interaction with Xoo strains;these findings will greatly facilitate research on the molecular mechanism of Xa7-mediated resistance and promote the use of this valuable gene in breeding.

关 键 词：Xa7 executor R gene durable resistance TALE bacterial blight RICE 

分 类 号：S435.111.47[农业科学—农业昆虫与害虫防治]