A Puccinia striiformis f. sp. tritici secreted protein activates plant immunity at the cell surface.
A Puccinia striiformis f. sp. tritici secreted protein activates plant immunity at the cell surface.
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DOI：
10.1038/s41598-017-01100-z
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发表时间：
2017-04-25
影响因子：
4.6
通讯作者：
Akkaya MS
中科院分区：
文献类型：
--
作者：
Dagvadorj B;Ozketen AC;Andac A;Duggan C;Bozkurt TO;Akkaya MS
病原体分泌效应蛋白抑制宿主免疫，介导营养吸收，从而使寄生。然而，在非适应性宿主上，效应物可以被宿主免疫受体检测为非自身，并激活非宿主免疫。然而，效应物触发的非宿主抗性的分子机制仍然未知。在这里，我们报告了一个小的富含半胱氨酸的蛋白质PstSCR 1从小麦锈病病原体条锈菌f。在非宿主茄科模式植物本氏烟草（Nicotiana benthamiana）中，小球藻（Pst）激活免疫。PstSCR 1同源物在Pst中被发现是保守的，并且在其最近的亲戚，Puccinia graminis f.小麦锈菌（Puccinia triticina）。当PstSCR 1在N.在本塞姆氏藻中，它用它的信号肽激发植物免疫系统，而当它在没有它的信号肽的情况下表达时，没有观察到刺激。PstSCR 1在N.本氏菌显著降低卵菌病原体的感染能力。此外，质外体靶向的PstSCR 1以剂量依赖性方式触发植物细胞死亡。然而，在类甾醇不敏感的1-相关激酶1（SERK 3/BAK 1）中，N. benthamiana，细胞死亡显著减少。纯化的PstSCR 1蛋白激活了N.本萨米亚纳我们的研究结果表明，Pst分泌的蛋白，PstSCR 1可以激活表面介导的免疫在非适应主机，并有助于非主机的电阻。
Pathogens secrete effector proteins to suppress host immunity, mediate nutrient uptake and subsequently enable parasitism. However, on non-adapted hosts, effectors can be detected as non-self by host immune receptors and activate non-host immunity. Nevertheless, the molecular mechanisms of effector triggered non-host resistance remain unknown. Here, we report that a small cysteine-rich protein PstSCR1 from the wheat rust pathogen Puccinia striiformis f. sp. tritici (Pst) activates immunity in the non-host solanaceous model plant Nicotiana benthamiana. PstSCR1 homologs were found to be conserved in Pst, and in its closest relatives, Puccinia graminis f. sp. tritici and Puccinia triticina. When PstSCR1 was expressed in N. benthamiana with its signal peptide, it provoked the plant immune system, whereas no stimulation was observed when it was expressed without its signal peptide. PstSCR1 expression in N. benthamiana significantly reduced infection capacity of the oomycete pathogens. Moreover, apoplast-targeted PstSCR1 triggered plant cell death in a dose dependent manner. However, in Brassinosteroid insensitive 1-Associated Kinase 1 (SERK3/BAK1) silenced N. benthamiana, cell death was remarkably decreased. Finally, purified PstSCR1 protein activated defence related gene expression in N. benthamiana. Our results show that a Pst-secreted protein, PstSCR1 can activate surface mediated immunity in non-adapted hosts and contribute to non-host resistance.