Non-TAL Effectors From Xanthomonas oryzae pv. oryzae Suppress Peptidoglycan-Triggered MAPK Activation in Rice
Non-TAL Effectors From Xanthomonas oryzae pv. oryzae Suppress Peptidoglycan-Triggered MAPK Activation in Rice
复制标题
龙菊英，宋从峰，严芳，周俊辉，周焕斌，杨冰，米黄单胞菌米白叶枯病菌的非TAL效应子抑制水稻中肽聚糖触发的MAPK激活
DOI：
10.3389/fpls.2018.01857
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发表时间：
2018-12-12
影响因子：
5.6
通讯作者：
Yang, Bing
中科院分区：
文献类型：
--
作者：
Long, Juying;Song, Congfeng;Yang, Bing
水稻白水稻白叶枯病的病原菌oryzae依靠其III型分泌系统和相关效应蛋白在水稻植株的维管组织中生长和定殖。III型效应子包括一类密切相关的转录激活子样（TAL）效应子和其余的不同效应子，即所谓的非TAL效应子。我们对水稻枯萎病发病机制中的非TAL效应物的了解仍然有限。本文报道了一种快速检测水稻叶肉原生质体中丝裂原活化蛋白激酶途径活化的方法。oryzaepv.并筛选能够抑制病原体相关的分子模式触发的免疫（PTI）应答的毒性效应物。在水稻细胞中瞬时表达的17个非TAL效应子中，我们发现3个效应子（XopZ、XopN和XopV）能够抑制肽聚糖触发的MAPK激活。X的三重变异体。oryzaepv.缺乏XopZ、XopN和XopV的水稻菌株PXO99（A）表现出加性降低的毒力。将两个基因中的任何一个加回去都恢复了三重突变体的毒力。本研究结果表明，非TAL效应子在水稻白叶枯病发病过程中具有群体性和冗余性的防御抑制能力。
Xanthomonas oryzae pv. oryzae, the causal pathogen of bacterial blight of rice, depends on its type III secretion system and associated effector proteins to grow and colonize the vascular tissues of rice plants. The type III effectors include a family of closely related transcription activator-like (TAL) effectors and the rest of diverse effectors, so-called non-TAL effectors. Our understanding of non-TAL effectors for pathogenesis in rice blight is still limited. Here we report a feasible method to rapidly detect the activation of mitogen-activated protein kinase pathway in rice mesophyll protoplasts by the X. oryzae pv. oryzae derived peptidoglycan and screen for virulent effectors that can suppress the pathogen-associated molecular pattern triggered immunity (PTI) response. Amongst 17 non-TAL effectors transiently expressed in rice cells, we found that three effectors (XopZ, XopN, and XopV) were able to suppress the peptidoglycan-triggered MAPK activation. The triple mutant of the X. oryzae pv. oryzae strain PXO99(A) lacking XopZ, XopN, and XopV showed additively reduced virulence. Adding back either of genes restored the virulence of the triple mutant. Our results demonstrate the collective and redundant ability of defense suppression by non-TAL effectors in causing bacterial blight of rice.