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
我们的前期研究发现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,但是其作用机制尚缺乏研究。本研究发现,U0126处理对玉米大斑病菌菌丝的电导率和PAL活性没有显著影响,但对POD活性和PPO活性均有显著影响；U0126对POD活性的影响具有浓度依赖性,即低浓度U0126促进POD活性升高,但高浓度U0126会抑制POD活性；U0126对PPO活性的影响具有菌株特异性。U0126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,但随着U0126浓度增加菌株01-19的PPO活性反而显著下降。以上研究结果表明,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有关；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。
英文摘要:
We have found that MAPK specific inhibitor U0126 has an important effect on the development of conidium and appressorium, HT-toxin production and pathogenicity of Setosphaeria turcica, however, its mechanism remains unclear. In this research, we found that U0126 had no significant effects 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 was concentration-dependent: their activity were increased under low U0126 concentration but reduced under high U0126 concentration. The effects of U0126 on PPO activity was 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/or fungal isolate-dependent.
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