The novel Cladosporium fulvum lysin motif effector Ecp6 is a virulence factor with orthologues in other fungal species
The novel Cladosporium fulvum lysin motif effector Ecp6 is a virulence factor with orthologues in other fungal species
复制标题
DOI：
10.1111/j.1365-2958.2008.06270.x
复制
发表时间：
2008-07-01
影响因子：
3.6
通讯作者：
Thomma, Bart P. H. J.
中科院分区：
文献类型：
--
作者：
Bolton, Melvin D.;van Esse, H. Peter;Thomma, Bart P. H. J.
在番茄叶片定殖过程中，生养真菌叶霉向质外体分泌几种效应蛋白。先前已经确定了8个效应器的特征，它们彼此之间或与其他真菌基因没有显着的同源性。为了发现可能在致病力中发挥作用的新的黄萎病效应因子，我们利用双向聚丙烯酰胺凝胶电泳法(2D-PAGE)对黄萎病病毒与番茄相互作用过程中分泌的蛋白质进行了可视化。鉴定了三种新的黄腐菌蛋白：CfPhiA、Ecp6和Ecp7。CfPhiA与真菌产孢子细胞中发现的被称为phialide的蛋白质同源。ECP6含有被认为是碳水化合物结合模块的溶素基序(LysM结构域)。ECP7编码一种小的、富含半胱氨酸的蛋白质，与已知的蛋白质没有同源性。外源ECP6基因的表达显著提高了番茄尖孢镰刀菌对番茄的致病力。此外，通过RNA干扰(RNAi)介导的基因沉默，我们证明了Ecp6对番茄黄萎病菌的致病作用。在全球范围内收集的黄腐菌菌株的Ecp6编码区几乎没有观察到任何等位基因变异。虽然到目前为止发现的黄萎菌效应因子在其他生物中没有明显的同源基因，但在各种真菌物种中都发现了保守的Ecp6同源基因。基于同源性的模拟表明，黄腐菌Ecp6的LysM结构域可能参与了几丁质的结合。
During tomato leaf colonization, the biotrophic fungus Cladosporium fulvum secretes several effector proteins into the apoplast. Eight effectors have previously been characterized and show no significant homology to each other or to other fungal genes. To discover novel C. fulvum effectors that might play a role in virulence, we utilized two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) to visualize proteins secreted during C. fulvum-tomato interactions. Three novel C. fulvum proteins were identified: CfPhiA, Ecp6 and Ecp7. CfPhiA shows homology to proteins found on fungal sporogenous cells called phialides. Ecp6 contains lysin motifs (LysM domains) that are recognized as carbohydrate-binding modules. Ecp7 encodes a small, cysteine-rich protein with no homology to known proteins. Heterologous expression of Ecp6 significantly increased the virulence of the vascular pathogen Fusarium oxysporum on tomato. Furthermore, by RNA interference (RNAi)-mediated gene silencing we demonstrate that Ecp6 is instrumental for C. fulvum virulence on tomato. Hardly any allelic variation was observed in the Ecp6 coding region of a worldwide collection of C. fulvum strains. Although none of the C. fulvum effectors identified so far have obvious orthologues in other organisms, conserved Ecp6 orthologues were identified in various fungal species. Homology-based modelling suggests that the LysM domains of C. fulvum Ecp6 may be involved in chitin binding.