贝莱斯芽孢杆菌SY01诱导苹果树抗性基因表达及其脂肽类抑菌物质分析OA北大核心CSTPCD

Bacillus velezensis SY01 has a strong inhibitory effect on the apple tree canker pathogen(Valsa mail var.pyri).In order to explore its prevention and control mechanism against apple tree canker,quantitative PCR was used to detect the effect of strain SY01 on the expression of key genes for apple tree canker disease resistance and to determine the composition of lipopeptide substances in strain SY01 by combining the expression difference analysis of the lipopeptide synthesis genes and UPLC-Triple TOF-M S/MS.The results showed that there were differences in the expression peak time of five key resistance-related genes in apple trees induced by strain SY01.MdNPR1,MdPDF1,MdPR2,and MdPR4 reached their peak at 24,72,72 and 48 h,respectively,while MdPR1 showed a sustained upward trend at 0-96 h.The crude extracts of antimicrobial lipopeptides of strain SY01 showed strong antibacterial activity under conditions of 20-40℃,natural light irradiation,ultraviolet irradiation,and pH 7 and had a good adaptability to natural light irradiation and UV irradiation.The amplification comparison analysis of lipopeptide inhibitory substance synthesis genes combined with UPLC-Triple TOF-MS/MS showed that strain SY01 could inhibit the growth of strain SW5 through the production of antimicrobial secondary metabolites such as Iturin,Fengycin and Surfactin.In summary,strain SY01 can inhibit the growth of apple tree canker fungus by inducing the expression of key resistance genes and secreting antimicrobial secondary metabolites for the control of apple tree canker disease.