灰葡萄孢丝裂原活化蛋白激酶编码基因bmp1和bmp3的功能

Function of mitogen-activated protein kinase encoding genes bmp1 and bmp3 in Botrytis cinerea

摘要:

【背景】植物病原真菌丝裂原活化蛋白激酶(Mitogen-activated protein kinase，MAPK)信号途径参与病菌有性生殖、细胞壁完整、菌丝侵染、致病力、胁迫响应等过程，灰葡萄孢MAPK信号途径参与病菌生长发育、致病力以及胁迫响应，但MAPK信号途径基因在灰葡萄孢中的功能尚未完全阐明，该信号途径对灰葡萄孢的生长发育和致病力的调控机制尚不明确。【目的】明确灰葡萄孢MAPK编码基因bmp1、bmp3在病菌生长发育、致病力以及氧化胁迫响应过程的功能，为进一步阐明MAPK信号途径调控灰葡萄孢生长发育和致病力的分子机制奠定基础。【方法】利用RNAi技术构建灰葡萄孢MAPK编码基因bmp1和bmp3的RNAi突变体，并以野生型BC22菌株为对照，对bmp1和bmp3基因的RNAi突变体的表型、致病力以及对氧化胁迫的敏感性进行分析。【结果】灰葡萄孢bmp1和bmp3基因的RNAi突变体其菌落形态、菌丝形态均与野生型BC22菌株没有明显差别；bmp1基因的RNAi突变体生长速率明显减慢，分生孢子产量明显降低；bmp3基因的RNAi突变体的生长速率与野生型BC22菌株没有明显差别，不能产生分生孢子。bmp1和bmp3基因的RNAi突变体在番茄果实的表面均不能产生明显的致病症状，而且不能穿透玻璃纸。bmp1基因的RNAi突变体在含有H2O2的培养基上受抑制的程度显著低于野生型，而在含甲萘醌的培养基上受抑制的程度显著高于野生型；bmp3基因的RNAi突变体在含有H2O2和甲萘醌的培养基受抑制的程度均显著高于野生型。【结论】灰葡萄孢bmp1基因正调控病菌生长、分生孢子形成、致病力和穿透能力，参与调控病菌对氧化胁迫的响应；灰葡萄孢bmp3基因正调控病菌分生孢子形成、致病力、穿透能力以及对氧化胁迫的响应。

Abstract:

[Background] Mitogen-activated protein kinase (MAPK) signaling pathway of plant pathogenic fungi is involved in sexual reproduction, cell wall integrity, mycelial infection, pathogenicity, stress response and other processes. The MAPK signaling pathway is involved in the growth, development, pathogenicity and stress response in Botrytis cinerea. However, the function of MAPK signaling pathway gene has not been fully elucidated in B. cinerea. [Objective] The objective of this study is to analyze the function of B. cinerea MAPK encoding genes bmp1 and bmp3 in growth, development, pathogenicity and response to oxidative stress, and to lay a foundation for clarifying the molecular mechanism of the MAPK signaling pathway in growth, development and pathogenicity in B. cinerea. [Methods] RNAi mutants of bmp1 and bmp3 genes were successfully constructed using RNAi technology. Compared with the wild-type strain BC22 (WT), phenotype, pathogenicity, and sensitivity to oxidative stress of bmp1 and bmp3 genes RNAi mutants were analyzed. [Results] The colony morphology and mycelia morphology of bmp1 and bmp3 gene RNAi mutants showed no obvious difference with WT. The bmp1 gene RNAi mutants grew slowly and produce fewer conidial. The growth rate of bmp3 gene RNAi mutants showed no obvious difference with WT. The bmp3 gene RNAi mutants did not produce conidia. RNAi mutants of bmp1 and bmp3 genes showed no pathogenicity and penetrating ability. RNAi mutants of bmp1 gene were significantly less inhibited than those of WT in the media containing H2O2, while the degree of inhibition was significantly higher in the media containing menadione than that of WT. RNAi mutants of bmp3 gene were significantly inhibited in H2O2 and menadione media than that of WT. [Conclusion] The bmp1 gene positively regulated growth, conidial formation, pathogenicity and penetrability, and was involved in the regulation of the response to oxidative stress in B. cinerea. The bmp3 gene positively regulates conidial formation, pathogenicity, penetrability, and response to oxidative stress in B. cinerea.