Mycosphaerella graminicola LysM Effector-Mediated Stealth Pathogenesis Subverts Recognition Through Both CERK1 and CEBiP Homologues in Wheat
Mycosphaerella graminicola LysM Effector-Mediated Stealth Pathogenesis Subverts Recognition Through Both CERK1 and CEBiP Homologues in Wheat
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DOI：
10.1094/mpmi-07-13-0201-r
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发表时间：
2014-03-01
影响因子：
3.5
通讯作者：
Kanyuka, Kostya
中科院分区：
文献类型：
--
作者：
Lee, Wing-Sham;Rudd, Jason J.;Kanyuka, Kostya
真菌细胞壁甲壳素是一种公认的病原体相关分子模式。通过模式识别受体识别植物中的甲壳素，激活病原体触发免疫(PTI)。在拟南芥中，这一过程是由质膜受体激酶CERK1介导的，而在水稻中，除了CERK1之外，还需要一个类似受体的蛋白CEBIP。分泌的几丁质结合裂解基序(LysM)含有真菌效应蛋白，如来自生物营养真菌叶霉的Ecp6，已被报道干扰PTI。在这里，我们鉴定了小麦CERK1和CEBIP的同源物，并研究了它们在与小麦禾谷分支杆菌(同义词ZymosepVictoria tritici)非生物营养病原菌相互作用中的作用。我们发现，利用大麦条纹花叶病毒介导的基因沉默来沉默小麦中的CERK1或CEBIP，足以使正常非致病的小麦根结线虫Meg3LysM(Ecp6的同源)缺失突变体允许叶片定植，而缺失突变体Mg1LysM对沉默的和野生型小麦叶片都是完全致病的。这些数据表明，Mg3LysM对于小麦叶片组织中PTI的真菌逃逸是重要的，CERK1和CEBIP都是激活几丁质诱导的防御所必需的，这一特征在水稻和小麦之间是保守的，可能在其他谷物物种中也是如此。
Fungal cell-wall chitin is a well-recognized pathogen-associated molecular pattern. Recognition of chitin in plants by pattern recognition receptors activates pathogen-triggered immunity (PTI). In Arabidopsis, this process is mediated by a plasma membrane receptor kinase, CERK1, whereas in rice, a receptor-like protein, CEBiP, in addition to CERK1 is required. Secreted chitin-binding lysin motif (LysM) containing fungal effector proteins, such as Ecp6 from the biotrophic fungus Cladosporium fulvum, have been reported to interfere with PTI. Here, we identified wheat homologues of CERK1 and CEBiP and investigated their role in the interaction with the nonbiotrophic pathogen of wheat Mycosphaerella graminicola (synonym Zymoseptoria tritici). We show that silencing of either CERK1 or CEBiP in wheat, using Barley stripe mosaic virus-mediated virus-induced gene silencing, is sufficient in allowing leaf colonization by the normally nonpathogenic M. graminicola Mg3LysM (homologue of Ecp6) deletion mutant, while the Mg1LysM deletion mutant was fully pathogenic toward both silenced and wild-type wheat leaves. These data indicate that Mg3LysM is important for fungal evasion of PTI in wheat leaf tissue and that both CERK1 and CEBiP are required for activation of chitin-induced defenses, a feature conserved between rice and wheat, and perhaps, also in other cereal species.