Functional Identification of Novel Cell Death-inducing Effector Proteins from Magnaporthe oryzae
Functional Identification of Novel Cell Death-inducing Effector Proteins from Magnaporthe oryzae
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DOI：
10.1186/s12284-019-0312-z
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发表时间：
2019-08-06
期刊：
影响因子：
5.5
通讯作者：
Chen, Songbiao
中科院分区：
文献类型：
--
作者：
Guo, Xinrui;Zhong, Debin;Chen, Songbiao
分泌效应蛋白在植物与真菌的相互作用中起着至关重要的作用。Magnaporthe oryzae基因组编码大量分泌蛋白。然而，大部分M. oryzae分泌蛋白的功能仍有待研究。我们之前鉴定了851个植物表达的m.o ryzae基因编码推定的分泌蛋白，并鉴定了5个m.o ryzae细胞死亡诱导蛋白MoCDIP1至MoCDIP5。在本研究中，我们扩大了对新型MoCDIP蛋白的鉴定工作。结果对98个植物表达的m.o ryzae推定分泌蛋白基因进行了瞬时表达实验，鉴定出8个诱导植物细胞死亡的新蛋白，分别为MoCDIP6 ~ MoCDIP13。酵母分泌实验和截断表达分析显示，除了MoCDIP8外，新型MoCDIPs的细胞死亡诱导活性需要导致蛋白质分泌到细胞外空间的信号肽。用重组MoCDIP6或MoCDIP7外源处理水稻幼苗可增强对稻瘟病菌的抗性，这表明这两种MoCDIPs可触发细胞死亡并引发水稻的防御反应。结论新鉴定的MoCDIP6 - MoCDIP13，以及先前鉴定的MoCDIP1 - MoCDIP5，为进一步解剖稻瘟病菌相互作用的分子机制提供了有价值的靶点。
Background Secreted effector proteins play critical roles in plant-fungal interactions. The Magnaporthe oryzae genome encodes a large number of secreted proteins. However, the function of majority of M. oryzae secreted proteins remain to be characterized. We previously identified 851 in planta-expressed M. oryzae genes encoding putative secreted proteins, and characterized five M. oryzae cell death-inducing proteins MoCDIP1 to MoCDIP5. In the present study, we expand our work on identification of novel MoCDIP proteins. Results We performed transient expression assay of 98 more in planta-expressed M. oryzae putative secreted protein genes, and identified eight novel proteins, MoCDIP6 to MoCDIP13, that induced plant cell death. Yeast secretion assay and truncation expression analysis revealed that the signal peptides that led the secretion of proteins to the extracellular space, were required for cell death inducing activity of the novel MoCDIPs except for MoCDIP8. Exogenous treatment of rice seedlings with recombinant MoCDIP6 or MoCDIP7 resulted in enhanced resistance to blast fungus, indicating that the two MoCDIPs trigger cell death and elicit defense responses in rice. Conclusions The newly identified MoCDIP6 to MoCDIP13, together with previously identified MoCDIP1 to MoCDIP5, provide valuable targets for further dissection of the molecular mechanisms underlying the rice-blast fungus interaction.