玉米弯孢叶斑病菌毒素对寄主防御酶系活性的影响及诱导抗性效应

 本文系统地研究了玉米弯孢叶斑病菌毒素对不同玉米抗性品种苯丙氨酸解氨酶(PAL)、过氧化物酶(PO)和超氧化物歧化酶(SOD)活性的影响及在一定条件下对寄主抗性的诱导效应。研究结果发现,抗病品种的PAL和PO酶活性比感病品种易被毒素激活,但抗病品种被毒素处理后的SOD活性明显低于感病品种,而且峰值出现得晚,这可能与抗病品种SOD活性的下降有利于积累活性氧、进一步激发寄主的抗性有关。此外,研究发现毒素在一定浓度下可作为抗性的诱导因子,为深入研究抗性机制和防病手段提供了新途径。

THE INFLUENCE OF Curvularia lunata TOXIN ON DEFENSE ENZYME ACTIVITIES AND ITS FUNCTION IN THE INDUCED RESISTANCE OF CORN

The influence of Curvularia lunata toxin on defense enzyme (PAL, PO and SOD) activities was studied in different varieties of corn, and the potential function of toxin as the inducer of resistance in corn was also investigated. Results suggested that the activities of PAL and PO were much more easily to be stimulated by toxin in resistant varieties than in susceptible ones, but on the contrary, the lower activity of SOD was found in resistant varieties when treated with toxin compared with that in susceptible ones. Based on the results, it was presumed that the lower activity of SOD would benefit the accumulation of active oxygen (AO) which was considered generally as an inducer of resistance. In addition, the research showed that the toxin at certain concentration could be used as an inducer of host resistance.