The autophagy-related gene CpAtg4 is required for fungal phenotypic traits, stress tolerance, and virulence in Cryphonectria parasitica.
The autophagy-related gene CpAtg4 is required for fungal phenotypic traits, stress tolerance, and virulence in Cryphonectria parasitica.
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自噬相关基因 CpAtg4 是 Cryphonectria parasitica 真菌表型性状、胁迫耐受性和毒力所必需的。
DOI：
10.1094/phyto-01-21-0015-r
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发表时间：
2021-05
期刊：
影响因子：
3.2
通讯作者：
Chen Baoshan
中科院分区：
文献类型：
--
作者：
Li Ru;Zhao LiJiu;Li ShuangCai;Chen FengYue;Qiu JinFeng;Bai LingYun;Chen Baoshan
自噬是一个进化上古老的过程，细胞能够分解细胞内的内容物，以支持正常的生理和发育。自噬体的形成受几种不同的蛋白质调控，包括关键的半胱氨酸蛋白酶Atg4。Atg4蛋白在板栗疫病病原菌Cryphonectria parasitica中的作用尚不完全清楚。在此背景下，我们旨在研究Atg4在寄生蜂自噬形成过程中的作用及其在非自噬事件中的作用。通过互补实验，我们确定了寄生菌CpAtg4基因能够功能性地补充酵母Atg4的缺失。利用酵母双杂交分析系统，我们证实了CpAtg4和CpAtg8直接相互作用，并确定了CpAtg4的377-409氨基酸与CpAtg8结合。CpAtg4缺失突变体未显示出MDC阳性染色，这表明CpAtg4是寄生蜂自噬所必需的。此外，ΔCpAtg4菌株在苹果和栗子茎上的菌丝形成和产孢量减少，毒力降低。ΔCpAtg4菌株对H2O2-和刚果红诱导的胁迫也更敏感。我们进一步确定了CpAtg4的377-409氨基酸对CpAtg4在体内的功能至关重要。综上所述，我们的研究结果表明，CpAtg4是寄生蜂自噬形成、真菌表型特征、胁迫耐受性和毒力所必需的。
Autophagy is an evolutionarily ancient process wherein cells are able to break down intracellular contents in order to support normal physiology and development. Autophagosome formation is regulated by several different proteins, including the key cysteine protease Atg4. The contribution of Atg4 protein in the pathogenic fungus Cryphonectria parasitica, which causes blight in chestnut plants, has not been completely understood. In this context, we aimed to investigate the role of Atg4 during autophagy formation and their contribution with non-autophagic events in C. parasitica. By complementation assay, we determined that the CpAtg4 gene from C. parasitica was able to functionally complement the deletion of yeast Atg4. Using a yeast two-hybrid assay system, we confirmed that CpAtg4 and CpAtg8 directly interact with one another, and amino acids 377-409 of CpAtg4 were identified as being responsible for its binding with CpAtg8. The deletion mutant of CpAtg4 did not demonstrate positive monodansylcadaverine (MDC) staining, which indicated that CpAtg4 is required for autophagy in C. parasitica. Moreover, the ΔCpAtg4 strain exhibited a decrease in aerial hyphae formation and sporulation, and reduction in virulence on apple and chestnut stem. The ΔCpAtg4 strains were also more sensitive to H2O2- and Congo red-induced stress. We further determined that amino acids 377-409 of CpAtg4 were essential for the function of CpAtg4 in vivo. Together, our findings indicated that CpAtg4 is required for the autophagy formation, fungal phenotypic traits, stress tolerance, and virulence in C. parasitica.