青枯菌诱导广藿香防御相关酶同工酶分析

Analysis on defense-related enzyme isozymes in Pogostemon cablin induced by Ralstonia solanacearum

目的研究青枯菌诱导广藿香的致病过程及防御相关酶同工酶的动态变化。方法利用青枯菌粗毒素诱导广藿香试管苗,并用聚丙烯酰胺凝胶电泳法,对诱导植株中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)同工酶谱带的变化进行分析。结果青枯菌诱导1～7 d后的广藿香植株,表现渐进的发病过程,开始时,植株失绿、少数叶片萎垂;逐渐植株茎杆弯曲、整株叶片萎蔫。同工酶电泳分析表明,SOD同工酶在第1、3天时分别出现了新谱带,与对照共有的谱带,强度先增后减;CAT同工酶在第3、5天时分别出现新谱带,第6天时强度达到最大;POD同工酶在第1、4天时分别出现了新谱带,强度先增后减,第7天时所有谱带消失。结论青枯病的发生呈现渐进的过程。青枯菌诱导1～7 d,广藿香SOD、CAT和POD同工酶谱带在数目和强度上均有所不同,呈动态变化,表明SOD、CAT和POD在广藿香抵抗青枯菌入侵时可能起到较为重要的作用。

Objective To investigate the pathogenesis process and the dynamic change of defense-related enzyme isozymes in Pogostemon cablin induced by Ralstonia solanacearum.Methods The crude toxin from R.solanacearum was used to induce the test-tube plantlets of P.cablin and polyacrylamide gel electrophoresis was used to analyze the isozyme bands changes of superoxide dismutase（SOD）,catalase（CAT）,and peroxidase（POD） in induced plants.Results P.cablin represented progressive pathogenesis during the R.solanacearum induction.Initially,the plants became gray-green and a few leaves wilted.Along with the disease developing,the stems of the plants were bending down and the whole plants wilted.The isozyme electrophoresis showed that new SOD bands emerged on the days 1 and 3,respectively,the strength of common bands of both the control and induced plants increased at first and then decreased.New CAT bands emerged on days 3 and 5,respectively,and achieved maximum strength on day 6.And new POD bands emerged on days 1 and 4,respectively,and the strength of the bands increased at first and then decreased,and all the bands disappeared on day 7.Conclusion The occurrence of bacterial wilt shows a gradual process.SOD,CAT,and POD isozymes represent dynamic change in P.cablin induced by R.solanacearum from 1—7 d,and the differences occur in the numbers and the strength of the bands,indicating that these enzymes might play an important role in P.cablin defense against R.solanacearum.