Cleavage of PrePL by Lon promotes growth and pathogenesis in Magnaporthe oryzae
Cleavage of PrePL by Lon promotes growth and pathogenesis in Magnaporthe oryzae
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Lon 裂解 PrePL 可促进稻瘟病菌的生长和发病机制
DOI：
10.1111/1462-2920.15335
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发表时间：
2021-01-25
影响因子：
5.1
通讯作者：
Zhang, Shi-Hong
中科院分区：
文献类型：
--
作者：
Dang, Yuejia;Wei, Yi;Zhang, Shi-Hong
依赖于ATP的Lon酶通过调节III型分泌系统的表达在细菌发病中发挥作用；然而，Lon酶如何调控真菌的发病机制却知之甚少。我们之前研究了与真菌发病相关的Lon结合蛋白，它与最小的稻瘟病菌Lon结合蛋白PrePL相互作用。在这里，我们证明了Lon裂解PrePL并产生Pc，Pc是一种具有过氧化氢酶和过氧化物酶活性的胞外11 kDa异构体。Delta PrePL功能缺失菌株表现出更强的产孢量和加速疾病发展，表明在疾病进展中由PrePL控制的时间特异性负调控机制。截短的Pc和缺失Lon裂解位点的全长PrePL都不能补充Delta PrePL的表型，这表明全长PrePL和Pc都在真菌发育中发挥作用。针对线粒体的PrePL被Lon水解生成Pc，并积累在真菌质外体中。重要的是，重组Pc在渗透到选定的植物叶片后诱导植物防御反应和细胞死亡，表明它是一个无毒因子。因此，这项工作揭示了真菌Lon介导的途径中的一个新的致病因子。此外，我们的结果为了解全长蛋白及其裂解异构体在真菌发病机制中的功能提供了新的见解。
ATP-dependent Lon proteases function in bacterial pathogenesis by regulating the expression of the Type III secretion system; however, little is known about how Lon proteases regulate fungal pathogenesis. We previously investigated Lon-binding proteins involved in fungal pathogenesis that interact with PrePL, the smallest Magnaporthe oryzae Lon-binding protein. Here, we show that Lon cleaves PrePL and produces Pc, an extracellular 11-kDa isoform with catalase and peroxidase activity. The Delta PrePL loss-of-function strain showed stronger sporulation and accelerated disease development, suggesting a temporally specific negative regulatory mechanism controlled by PrePL in disease progression. Neither the truncated Pc, nor the full-length PrePL missing the Lon cleavage site complemented the Delta PrePL phenotype, suggesting that full-length PrePL and Pc both function in fungal development. PrePL targeted to the mitochondria undergoes hydrolysis by Lon to produce Pc, which accumulates in the fungal apoplast. Importantly, recombinant Pc induced plant defence responses and cell death after being infiltrated into selected plant leaves, indicating that it functions as an avirulence factor. This work thus reveals a novel pathogenic factor in the fungal Lon-mediated pathway. Additionally, our results provide new insight into the functions of a full-length protein and its cleaved isoform in fungal pathogenesis.