Identification and Characterization of Plant Cell Death-Inducing Secreted Proteins From Ustilaginoidea virens
Identification and Characterization of Plant Cell Death-Inducing Secreted Proteins From Ustilaginoidea virens
复制标题
黑粉菌植物细胞死亡诱导分泌蛋白的鉴定和表征。
DOI：
10.1094/mpmi-09-15-0200-r
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发表时间：
2016-05-01
影响因子：
3.5
通讯作者：
Sun, Wenxian
中科院分区：
文献类型：
--
作者：
Fang, Anfei;Han, Yanqing;Sun, Wenxian
稻曲病是一种子囊菌，引起水稻稻曲病，是水稻的重要病害之一。真菌效应分子在宿主-病原菌协同进化相互作用中起着至关重要的作用。然而，人们对尿毒杆菌效应器的功能知之甚少。在这里，我们对可能的效应因子进行了功能研究，证明119个可能的效应因子中有13个会导致烟草的坏死或坏死样表型。其中，利用酵母分泌系统确定了11个蛋白的分泌，除UV_44和UV_4753外，其余基因均在感染过程中高度诱导表达。已证实有8种分泌蛋白可在水稻原生质体中触发细胞死亡或防御，这些蛋白的分泌信号对它们的细胞死亡诱导活性是必不可少的。UV_44和UV_1423触发细胞死亡的能力分别依赖于预测的丝氨酸肽酶和核糖核酸酶催化活性部位。我们证明了UV_1423和UV_6205是N-糖基化蛋白，它们的糖基化对它们诱导细胞死亡的能力有不同的影响。总而言之，这项研究确定了在非寄主和寄主植物中具有特定结构基序的多种分泌蛋白，这些蛋白可以诱导细胞死亡或防御机制。
Ustilaginoidea virens (Cooke) Takah (telemorph Villosiclava virens) is an ascomycetous fungus that causes rice false smut, one of the most important rice diseases. Fungal effectors often play essential roles in host-pathogen coevolutionary interactions. However, little is known about the functions of U. virens effectors. Here, we performed functional studies on putative effectors in U. virens and demonstrated that 13 of 119 putative effectors caused necrosis or necrosis-like phenotypes in Nicotiana benthamiana. Among them, 11 proteins were confirmed to be secreted, using a yeast secretion system, and the corresponding genes are all highly induced during infection, except UV_44 and UV_4753. Eight secreted proteins were proven to trigger cell death or defenses in rice protoplasts and the secretion signal of these proteins is essential for their cell death-inducing activity. The ability of UV_44 and UV_1423 to trigger cell death is dependent on the predicted serine peptidase and ribonuclease catalytic active sites, respectively. We demonstrated that UV_1423 and UV_6205 are N-glycosylated proteins, which glycosylation has different impacts on their abilities to induce cell death. Collectively, the study identified multiple secreted proteins in U. virens with specific structural motifs that induce cell death or defense machinery in nonhost and host plants.