枯草芽胞杆菌YB-05对小麦全蚀病菌胞内酶活的影响

Effect of Bacillus subtilis YB-05 Fermentation Broth on Gaeumannomyces gramini Enzyme Activities

小麦全蚀病菌是影响小麦产量和质量的主要致病菌之一,前期研究表明枯草芽胞杆菌YB-05对小麦全蚀病菌的生长具有抑制作用。本试验拟通过研究该菌对小麦全蚀病菌相关酶系的诱导变化情况,解析其对小麦全蚀病菌的抑制作用机理。本试验以小麦全蚀病菌Gaeumannomyces gramini(Sacc.)Arx et Oliver var.tritici(Sacc.)Walker为靶标菌,加入终浓度为MIC50枯草芽胞杆菌YB-05发酵液,通过显微镜观察菌株YB-05发酵液对小麦全蚀病菌菌丝结构和形态的影响,通过酶活力测定检测菌株YB-05发酵液对小麦全蚀病菌胞内苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)和超氧化物歧化酶(SOD)防御酶活的影响,同时检测菌株YB-05发酵液在离体/活体条件下对小麦全蚀病菌线粒体复合酶Ⅱ/Ⅲ活力的影响。小麦全蚀病菌经菌株YB-05发酵液处理后,显微镜观察到其菌丝变粗、断裂,顶端膨大,分枝增多;处理8 d后,胞内的PAL、POD、CAT、PPO和SOD活性比对照依次高24.52%、72.67%、81.81%、80.36%和112.48%;离体条件处理,线粒体复合酶Ⅱ和Ⅲ的活性与对照组相比差异不显著,而活体条件处理下差异显著,线粒体复合酶Ⅱ和Ⅲ分别比对照组分别降低43.95%和55.87%。菌株YB-05发酵液通过结合小麦全蚀病菌线粒体复合酶Ⅱ和Ⅲ的相关基因,从而影响该基因的表达,抑制小麦全蚀病菌线粒体复合酶Ⅱ和Ⅲ的活力,影响小麦全蚀病菌的呼吸,进而导致抑制小麦全蚀病菌菌丝畸变,从而影响小麦全蚀病菌的正常生长。

Wheat take-all pathogen is one of the main pathogenic funguses which exert influences on yield and quality of wheat,there have previous studies to prove that biocontrol strain B.subtilis YB-05 inhibits the growth of wheat take-all pathogen.This study intended to study the changes of the related enzymes in wheat take-all pathogen which were induced by B.subtilis YB-05,and explored the inhibit ion mechanism of B.subtilis YB-05 fermentat ion broth against wheat take-all pathogen.Wheat take-all pathogen was treated with B.subtilis YB-05fermentat ion broth which the concentrat ion reached MIC50,the effects of B.subtilis YB-05 fermentat ion broth on mycelium structure and morphology of wheat take-all pathogen were observed by microscope;CAT,POD,PPO,SOD and PAL act ivity of wheat take-all pathogen were detected through enzyme activity assay,at the same time the enzymat ic activit ies of mitochondrial enzyme complexes Ⅱ and Ⅲ of wheat take-all pathogen in vitro/vivo were studied.The results showed that B.subtilis YB-05 fermentat ion broth resulted in aberrant growth of wheat take-all pathogen;The enzymat ic activit ies of PAL,POD,CAT,PPO and SOD in wheat take-all pathogen treated with B.subtilis YB-05 fermentat ion broth for 8 day were 24.52%,72.67%,81.81%,80.36% and 112.48%,lower than the control group,respect ively;The enzymat ic activit ies of mitochondrial enzyme complexes Ⅱ and Ⅲwere not changed signif icantly with the control in vitro.However,the enzymat ic activit ies of mitochondrial enzyme complexes Ⅱ and Ⅲ were lower 43.95% and 55.87% than the control group in vivo,respectively.B.subtilis YB-05 fermentat ion broth affected the gene express ion by combining the related genes of mitochondrial enzyme complexes Ⅱ and Ⅲ in wheat take-all pathogen,and then reduced the respiratory metabolism of wheat take-all pathogen by inhibit ing the mitochondrial enzyme complexes Ⅱ and Ⅲ enzymat ic activity,and finally caused the growth inhibition.