A novel Meloidogyne graminicola effector, MgGPP, is secreted into host cells and undergoes glycosylation in concert with proteolysis to suppress plant defenses and promote parasitism.
A novel Meloidogyne graminicola effector, MgGPP, is secreted into host cells and undergoes glycosylation in concert with proteolysis to suppress plant defenses and promote parasitism.
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一种新型的禾本科根结线虫效应子 MgGPP 被分泌到宿主细胞中，并与蛋白水解作用一起进行糖基化，以抑制植物防御并促进寄生
DOI：
10.1371/journal.ppat.1006301
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发表时间：
2017-04
期刊：
影响因子：
6.7
通讯作者：
Liao J
中科院分区：
文献类型：
--
作者：
Chen J;Lin B;Huang Q;Hu L;Zhuo K;Liao J
植物病原体效应子可以通过激活宿主的翻译后修饰（PTM）来调节其活性，从而促进其寄生，但在植物寄生线虫领域，这一现象的研究较少。在这项研究中，我们表明，植物寄生线虫禾生根结线虫已经进化出一种新的效应，MgGPP，这是专门表达在线虫亚腹食道腺细胞和上调的早期寄生阶段的M。禾生菌效应子MgGPP在线虫寄生中起作用。表达MgGPP的转基因水稻品系对M.与野生型对照植物相比，在植物中，通过RNAi技术沉默MgGPP显著增加了水稻对M.草生菌。值得注意的是，我们表明MgGPP分泌到宿主植物中并靶向ER，其中MgGPP的N-糖基化和C-末端蛋白水解发生。C-末端蛋白水解促进MgGPP离开ER，之后其被转运到细胞核。此外，MgGPP的N-糖基化是抑制宿主应答所必需的。这些研究数据提供了一个有趣的例子，植物糖基化与病原体效应物的蛋白水解相结合，描绘了一种新的机制，寄生线虫可以通过这种机制征服植物免疫力并促进寄生，并可能为开发新的抗线虫感染策略提供一个有前途的目标。
Plant pathogen effectors can recruit the host post-translational machinery to mediate their post-translational modification (PTM) and regulate their activity to facilitate parasitism, but few studies have focused on this phenomenon in the field of plant-parasitic nematodes. In this study, we show that the plant-parasitic nematode Meloidogyne graminicola has evolved a novel effector, MgGPP, that is exclusively expressed within the nematode subventral esophageal gland cells and up-regulated in the early parasitic stage of M. graminicola. The effector MgGPP plays a role in nematode parasitism. Transgenic rice lines expressing MgGPP become significantly more susceptible to M. graminicola infection than wild-type control plants, and conversely, in planta, the silencing of MgGPP through RNAi technology substantially increases the resistance of rice to M. graminicola. Significantly, we show that MgGPP is secreted into host plants and targeted to the ER, where the N-glycosylation and C-terminal proteolysis of MgGPP occur. C-terminal proteolysis promotes MgGPP to leave the ER, after which it is transported to the nucleus. In addition, N-glycosylation of MgGPP is required for suppressing the host response. The research data provide an intriguing example of in planta glycosylation in concert with proteolysis of a pathogen effector, which depict a novel mechanism by which parasitic nematodes could subjugate plant immunity and promote parasitism and may present a promising target for developing new strategies against nematode infections.