Characterization of the Papain-Like Protease p29 of the Hypovirus CHV1-CN280 in Its Natural Host Fungus Cryphonectria parasitica and Nonhost Fungus Magnaporthe oryzae
Characterization of the Papain-Like Protease p29 of the Hypovirus CHV1-CN280 in Its Natural Host Fungus Cryphonectria parasitica and Nonhost Fungus Magnaporthe oryzae
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天然宿主真菌 Cryphonectria parasitica 和非宿主真菌 Magnaporthe oryzae 中低病毒 CHV1-CN280 的类木瓜蛋白酶 p29 的表征
DOI：
10.1094/phyto-08-18-0318-r
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发表时间：
2019
期刊：
影响因子：
3.2
通讯作者：
Cheng Qiang
中科院分区：
文献类型：
--
作者：
Xiong Qin;Zhang Linqiao;Waletich Justin;Zhang Linlin;Zhang Chen;Zheng Xinyue;Qian Yulin;Zhang Zhengguang;Wang Yuanchao;Cheng Qiang
栗疫病弱毒1号（CHV 1-CN280）是从我国北方地区分离到的一株具有典型弱毒特征的病毒。我们曾报道CHV 1-CN280比CHV 1-EP 713和CHV 1-Euro 7具有更强的攻击性和更强的水平传播能力，因此在栗疫病的生物防治上显示出更大的潜力。CHV 1-CN 280的基因组序列与其他三种次病毒（CHV 1-EP 713、CHV 1-Euro 7和CHV 1-EP 721）具有约70%的同一性。p29是一种由CHV 1-CN 280低病毒编码的木瓜样蛋白酶，其编码区平均仅显示约60%的氨基酸同一性，而其他三个CHV 1分离株之间的同一性高于89%。蛋白酶p29作为一种病毒编码的决定因素，负责改变其他CHV 1分离株的真菌宿主表型。本研究探讨了CHV 1-CN280 p29基因在无病毒C.寄生虫进行了调查。CHV 1-CN280 p29在C.结果表明，该菌的产孢量、色素沉着、胞外漆酶活性和致病性均显著降低，这与以往的研究结果一致。随后，讨论了CHV 1-CN 280 p29作为病毒决定簇在其他植物病原真菌如稻瘟病菌中抑制宿主表型的潜力。而在M.结果表明，CHV 1-CN280 p29对水稻细菌的产孢、胞外漆酶活性和致病性有相反的影响，对色素形成和菌丝生长无明显影响，但对胞外过氧化物酶活性有促进作用，表明CHV 1-CN280 p29可能干扰了水稻细菌的一条独特的调控途径。寄生，而不是一个基本的调控途径保守的各种真菌。另外，CHV 1-CN280 p29介导的真菌表型调节可能是通过p29和一种特殊的真菌宿主成分之间的特异性相互作用来促进的，该成分只存在于C.寄生但不寄生M.米。
Cryphonectria hypovirus 1strain CN280 (CHV1-CN280) was isolated from North China and exhibited typical hypovirulence-associated traits. We previously reported that CHV1-CN280 was more aggressive and had a higher horizontal transmission ability betweenCryphonectria parasiticaisolates belonging to different vegetative compatibility groups than two other CHV1 hypoviruses (namely, CHV1-EP713 and CHV1-Euro7), thus displaying greater potential for biological control of chestnut blight. The genome sequence of CHV1-CN280 shared approximately 70% identity with three other hypoviruses (CHV1-EP713, CHV1-Euro7, and CHV1-EP721). The coding region for p29, a papain-like protease encoded by CHV1-CN280 hypovirus, displayed an average of only approximately 60% amino acid identity among them, while the identity between the other three CHV1 isolates was higher than 89%. Protease p29 acted as a virus-encoded determinant responsible for altering fungal host phenotypes in other CHV1 isolates. In this study, the impacts of CHV1-CN280p29expression in virus-freeC. parasiticawere investigated. CHV1-CN280p29expression inC. parasiticaresulted in significantly reduced sporulation, pigmentation, extracellular laccase activities, and pathogenicity, which is consistent with previous investigations. Subsequently, the potential of CHV1-CN280 p29 as a viral determinant responsible for suppression of host phenotypes in other phytopathogenic fungi such asMagnaporthe oryzae,the causal agent of rice blast disease, was discussed. However, heterologous expression ofp29inM. oryzaeinduced the opposite effect on sporulation, extracellular laccase activities, and pathogenicity; had no significant effect on pigmentation and mycelial growth; and contributed to extracellular peroxidase activities, suggesting that CHV1-CN280 p29 may disturb a unique regulatory pathway inC. parasitica, rather than a basic regulatory pathway conserved in diverse range of fungi. Alternatively, CHV1-CN280 p29-mediated modulation of fungal phenotypes may be facilitated by the specific interaction between p29 and a special fungal-host component, which exists only withC. parasiticabut notM. oryzae.