芽孢杆菌Ya-1诱导辣椒防御酶活性提高和相关抗病基因的表达

Increase of Defense Enzyme Activity and Expression of Resistance-related Genes in Pepper Induced by Bacillus sp.Ya-1

芽孢杆菌Ya-1对辣椒枯萎病有较好的防治效果。为明确其是否具有诱导辣椒抗枯萎病的能力,本研究采用“浸根+灌根”法接种辣椒幼苗,分析不同处理前后辣椒叶片苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、超氧化物歧化酶(SOD)的活性及丙二醛(MDA)含量的变化。同时,RT-PCR分析了抗性相关蛋白PR-1、POD酶和SOD酶合成相关基因POD和SOD1的转录表达情况。结果表明,Ya-1处理后辣椒叶片PAL、POD和SOD活性较处理前显著上升,而MDA含量显著下降;抗性相关蛋白PR-1、防御酶相关基因POD和SOD1表达水平明显上调。本研究说明诱导辣椒产生抗病性是Ya-1防治辣椒枯萎病的机理之一。

Bacillus sp.Ya-1 could suppress Fusarium wilt of pepper.In order to explore the potential mechanism underlying the induced resistance mediated by Ya-1,pepper seedlings were inoculated with’root immersion and root irrigation’method in this study.And the changes of activities of phenylalanine ammonia-lyase(PAL),peroxidase(POD),superoxide dismutase(SOD)and malondialdehyde(MDA)content in pepper leaves before and after different treatments were analyzed.At the same time,RT-PCR was used to analyze the transcriptional expression of several enzymes synthesis-related genes,POD,SOD1 and defense-related gene PR-1.The results showed that levels of SOD,POD,PAL activities and SOD1,POD,PR-1 were all significantly higher than those of the control,while the level of MDA was significantly lower.The expression level of PR-1,POD and SOD1 were significantly enhanced after root immersion and root irrigation with Ya-1 fermentation broth.The above results suggested that the induced resistance in pepper by Ya-1 might be one of the mechanisms to control pepper Fusarium wilt caused by F.oxysporum.