水稻Xa7基因抗白叶枯病应答中的活性氧代谢分析

摘要

Bacterial blight (BB) , caused by Xanthomonas oryzae pv. Oryzae, is one of the most serious worldwide disease of rice. Xal is a broadly dominant resistance gene directed against BB. The resistant rice cultivar IRBB7 (with Xal) and susceptible control IR24 were inoculated with strain PXO86 of BB. Comparison to the IR24, the leaves of IRBB7 accumulated reactive oxygen species ( ROS; H2O2 and 02- ) faster and higher, the activity of active oxygen metabolism-related enzymes (SOD, CAT, APX and POD) of IRBB7 was higher in the infect site. It was suggested that the regulation of ROS metabolism might be helpful for the Xal-mediated disease resistance response.%白叶枯病是由革兰氏阴性黄单孢菌水稻变种(Xanthomonas oryzae pv.Oryzae,Xoo)所引起的一种世界性水稻细菌病害.水稻Xa7基因是一个具有广谱抗性的显性抗白叶枯病基因.通过对水稻抗病品种IRBB7(含Xa7)和感病对照IR24接种白叶枯菌PXO86,发现:在叶片的病原菌侵染部位,IRBB7比IR24的活性氧(H2O2和O2-)积累更快且含量更高；与活性氧代谢相关的酶,如超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和过氧化物酶的活性也更高.推测活性氧的代谢调节可能在Xa7基因介导的抗病反应中起作用.