R gene expression induced by a type-III effector triggers disease resistance in rice
R gene expression induced by a type-III effector triggers disease resistance in rice
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DOI：
10.1038/nature03630
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发表时间：
2005-06-23
期刊：
影响因子：
64.8
通讯作者：
Yin, ZC
中科院分区：
文献类型：
--
作者：
Gu, KY;Yang, B;Yin, ZC
植物中的抗病性（R）基因编码专门识别不兼容的病原体并触发一系列事件导致宿主植物抗病性的事件（1）。 R-GENE特异性由病原体中的宿主R基因和同源性空白（AVR）基因决定（2,3）。但是，基因特异性的基础尚不清楚。在这里，我们报告了从大米和Xanthomonas oryzae PV的Cognate AVR基因AVRXA27的R Gene XA27克隆。 oryzae。 XA27的抗性和易感等位基因编码相同的蛋白质。但是，只有抗性等位基因的表达才能在水稻植物受到携带Avrxa27的细菌挑战时发生的，其产物是核局部局部IIIIIII型效应子。 XA27的诱导仅发生在感染组织的附近，而XA27的异位表达导致病原体的其他兼容菌株的抗性。因此，XA27对不兼容病原体的特异性涉及在AVRXA27效应子的存在下R基因的差异表达。
Disease resistance (R) genes in plants encode products that specifically recognise incompatible pathogens and trigger a cascade of events leading to disease resistance in the host plant(1). R-gene specificity is dictated by both host R genes and cognate avirulence (avr) genes in pathogens(2,3). However, the basis of gene-for-gene specificity is not well understood. Here, we report the cloning of the R gene Xa27 from rice and the cognate avr gene avrXa27 from Xanthomonas oryzae pv. oryzae. Resistant and susceptible alleles of Xa27 encode identical proteins. However, expression of only the resistant allele occurs when a rice plant is challenged by bacteria harbouring avrXa27, whose product is a nuclear localized type-III effector. Induction of Xa27 occurs only in the immediate vicinity of infected tissue, whereas ectopic expression of Xa27 resulted in resistance to otherwise compatible strains of the pathogen. Thus Xa27 specificity towards incompatible pathogens involves the differential expression of the R gene in the presence of the AvrXa27 effector.