特异性MAPK抑制剂U0126对玉米大斑病菌细胞膜透性及防御酶活性的影响

依据实验室前期研究发现,MAPK特异性抑制剂U0126对玉米大斑病菌分生孢子及附着胞发育、HT-毒素的产生和活性以及致病性都有着较显著的影响。以不同浓度的U0126处理玉米大斑病菌菌株,研究该抑制剂对病菌细胞膜透性及防御酶活性的影响。结果表明,U0126对病菌菌丝电导率和PAL活性均无显著影响,但对POD及PPO活性均有显著影响,且U0126对POD活性的影响具有浓度依赖性,即低浓度U0126可提高POD活性,高浓度U0126抑制POD活性;U0126对PPO活性的影响具有菌株特异性,且对菌株01-27的PPO活性的影响与对POD活性的影响相似,都具有浓度依赖性;随着U0126浓度增加菌株01-19的PPO活性反而显著下降。U0126对玉米大斑病菌细胞膜透性和苯丙氨酸代谢没有显著影响,但与过氧化物代谢和多酚代谢密切相关;U0126对过氧化物代谢和多酚代谢的影响具有一定的菌株特异性和浓度依赖性。

Effects of Specific MAPK Inhibitor U0126 on the Cell Membrane Permeability and Defense Enzyme Activity of Setosphaeria turcica

MAPK specific inhibitor U0126 had an obvious effect on the development of conidium and appressorium, HT-toxin production and pathogenicity of Setosphaeria turcica. In this research, different concentrations of U0126 were used to deal with different strains to detect the effect of the inhibitor on membrane permeability and defense enzyme activity of S.turcica. The result showed that U0126 had no significant effect on the hypha electric conductivity and PAL activity, but could significantly affect the activities of POD(Peroxidase) and PPO(Polyphenolic oxidase). The effects of POD activity were concentration-dependent: the activity increased under low concentration but reduced under high concentration treatment. The effects of U0126 on PPO activity were fungal isolate-specific: the effects on PPO activity of isolate 01-27 were concentration-dependent, but the PPO activity reduced as the increase of U0126 concentration. The results demonstrated that there were no effects of U0126 on the hypha cell membrane permeability and phenylalanine metabolism, but the functions of U0126 were related to peroxide metabolism and polyphenol metabolism under the action of concentration-dependent and fungal isolate-dependent.