茉莉酸甲酯对水稻白叶枯病的诱导抗性及相关防御酶活性的影响

Effect of methyl jasmonate on induced resistance of rice seedlings against bacterial leaf blight and activities of related defense enzymes

为探索茉莉酸甲酯(methyl jasmonate,MeJA)诱导水稻抗白叶枯病的效应,采用MeJA喷雾处理剪叶接种法,测定MeJA对水稻幼苗的白叶枯病病情指数、白叶枯病病菌Xanthomonas oryzae pv.oryzae的抑菌效果及对叶片过氧化物酶(peroridase,POD)、过氧化氢酶(catalase,CAT)、超氧化物歧化酶(su-peroxide dismutase,SOD)、多酚氧化酶(polyphenol oxidase,PPO)和苯丙氨酸解氨酶(phenylalnaineammonialyase,PAL)等相关防御酶活性的影响。0.05～2.0 mmol/L的MeJA能降低水稻幼苗白叶枯病的病情指数,但对水稻白叶枯病菌无直接抑菌活性;0.1 mmol/L MeJA的诱导效果最好,处理48h后,感病品种温229和抗病品种嘉早312的诱导效果分别为73.18%和70.43%;0.05～2.0mmol/L的MeJA处理水稻叶片中POD、CAT、SOD、PPO和PAL活性呈上升趋势。研究表明MeJA能诱导水稻幼苗对白叶枯病的抗性,且诱导抗性的产生与MeJA提高水稻相关防御酶的活性有关。

Abstract ： To explicate the effect of methyl jasmonate （MeJA） on induced resistance against rice bacteri- al leaf blight, the disease indexes of the rice seedlings inoculating with Xan.thomonas oryzae pv. oryzae were measured by treating with MeJA at different concentrations. Inhibition effects of MeJA were also an- alyzed on X. oryzae and activities of related defense enzymes such as peroridase （POD）, catalase （CAT） , superoxide dismutase （ SOD ） , polyphenol oxidase （ PPO ） and phenylalnaine ammonialyase （PAL）. The results showed that 0.05 -2.0 mmol/L MeJA decreased the disease indexes of rice bacterial blight, but had no direct inhibition effects on X. oryzae. MeJA at 0.1 mmol/L for 48 h had the strongest induced effects with 73.18% on the susceptible rice variety Wen229 and 70.43% on the resistant varietyJiazao312, respectively. MeJA at 0.05-2.0mmol/L increased the activities of POD, CAT, SOD, PPO and PAL in general. These results indicated that MeJA induced rice resistance against rice bacterial leaf blight which related to the increased activities of defense enzymes caused by MeJA.