苏云金芽胞杆菌4BM1菌株对油菜菌核病的防治潜力OA北大核心CSTPCD

[Objective]In the previous study,Bacillus thuringiensis 4BM1 strains effectively suppressed Sclerotinia sclerotiorum growth by inducing systemic resistance in Brassica campestris.The induced systemic resistance mechanism and biocontrol potential were studied,which may provide strain resources for the biological control of sclerotiniose.[Method]Quantitative real-time PCR and transcriptome sequencing were used to analyze the transcription levels of defense-related genes in B.campestris leaves after roots were exposed to the Bt 4BM1 strain.The disease-resistance related secondary metabolites biosynthesis gene clusters were predicted by using the complete genome sequence of Bt 4BM1 strain and the antiSMASH 2.0 software.The 4BM1 strain was inoculated into the potted B.campestris seedlings by fermentation liquid irrigation method,and its colonization ability and growth promotion effect were analyzed.[Result]4BM1 strain triggered hypersensitive response in B.campestris leaves.Genes involved in salicylic acid,jasmonic acid,ethylene signaling and brassinosteroid synthesis pathways of B.campestris leaves were upregulated after the roots were exposed to the Bt 4BM1 strain.The candidate gene clusters involved in exopolysaccharide and 13 other disease-resistance related secondary metabolites biosynthesis were predicted in 4BM1 strain chromosome.The 4BM1 strain colonized in the rhizosphere of B.campestris and promoted the growth of B.campestris.[Conclusion]4BM1 strain can be used as a potential biological control resource to control sclerotiniose and promote the growth of B.campestris seedlings.