特异性MEK抑制剂U0126对玉米大斑病菌孢子萌发、附着胞产生和致病性的影响

 【目的】研究MAPK信号转导途径对玉米大斑病菌生长、发育和致病性的调控作用，为明确玉米大斑病菌和玉米之间互作的分子机制奠定基础，对玉米大斑病的有效防治也有重要的理论意义。【方法】利用MEK特异性抑制剂U0126处理玉米大斑病菌，观测该抑制剂对玉米大斑病菌孢子萌发、附着胞发育和致病性的影响。【结果】U0126对玉米大斑的菌落形态和生长速度没有显著影响，可以形成正常的菌丝、分生孢子，但分生孢子萌发时间晚，芽管短，分生孢子萌发百分率和附着胞产生数目下降，玉米叶片的发病时间延迟2～3 d，发病率下降30%左右。在一定浓度范围内，U0126对分生孢子萌发和附着胞产生的抑制程度随着浓度增加而上升，但随着处理时间的延长而下降。【结论】玉米大斑病菌的分生孢子萌发、附着胞产生和对感病玉米叶片的致病能力受U0126抑制的MAPK信号转导途径调节。

Effects of the MEK-Specific Inhibitor U0126 on the Conidial Germination, Appressorium Production and Pathogenicity of Setosphaeria turcica

【Objective】Systematic studies on the effects of MAPK (Mitogen activated protein kinase) signal transduction pathway on the growth, development and pathogenicity of Setosphaeria turcica will not only help us to understand the molecular mechanism of pathogen-host interaction, but also benefit the effective control of the diseases caused by S. turcica.【Method】U0126, the specific MEK inhibitor, was used to treat S. turcica before observing the conidial germination, appressorium production and pathogenicity of the pathogen.【Result】There was no significant effect of U0126 on the pathogen's colony morphology and mycelium growth. After treatment with U0126, the mycelium and conidia were normal, but the conidial germination, appressorium production and pathogenicity to susceptible corn leaves were significantly inhibited. Under the definite concentration scope, U0126 increased the inhibition degree to conidial germination and appressorium production with the increase of U0126 concentration, but the inhibition degree decreased with elongation of the treatment time.【Conclusion】The conidial germination, appressorium production and pathogenecity to susceptive corn leaves are regulated by the MAPK pathway inhibited by U0126.