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【目的】初步明确高毒菌株VDG1特异片段SCF73与大丽轮枝菌致病力的关系。【方法】通过比较基因组学分析和PCR鉴定,明确大丽轮枝菌高毒菌株VDG1相对于低毒菌株VDG2的特异片段SCF73;构建SCF73片段敲除质粒,导入农杆菌AGL-1,应用农杆菌介导法转化大丽轮枝菌VDG1,抗性筛选和PCR扩增鉴定SCF73敲除转化子;利用果胶、纤维素和淀粉培养基模拟分析ΔSCF73降解细胞壁组分的能力,采用定量蘸根接种法鉴定其对感病棉种军棉1号的致病力。【结果】确定了大丽轮枝菌VDG1的特异片段SCF73,长度为27.1 kb,预测编码5个基因,推测2个基因具有水解酶功能;筛选获得了3个ΔSCF73突变株;突变株利用细胞壁组分的能力与野生型菌株VDG1相比无显著差异;突变株对感病棉种军棉1号的致病力显著减弱。【结论】高毒力菌株VDG1特异片段SCF73在大丽轮枝菌致病过程中具有重要作用。
【Objective】 To clarify the relationship between virulence strain VDG1 specific fragment SCF73 and pathogenicity of Verticillium dahliae. 【Method】 The specific fragment of VDG1 against VDG2 was screened out by comparative genomics analysis and PCR. SCF73 fragment was constructed and introduced into Agrobacterium tumefaciens AGL-1. Agrobacterium tumefaciens Mediated transformation of V. dahliae VDG1, resistance screening and PCR amplification to identify SCF73 knockout transformants; using pectin, cellulose and starch medium simulating the ability of ΔSCF73 to degrade cell wall components, using quantitative dipping root inoculation Act identification of the susceptible cotton Junmian 1 pathogenicity. 【Result】 The specific fragment of VDG1 of V. dahliae was identified as SCF73, with a length of 27.1 kb. Five genes were predicted and predicted to be hydrolase-degrading. Three ΔSCF73 mutants were selected and screened. There was no significant difference in the ability of the mutant strain compared with the wild-type strain VDG1. The virulence of the mutant strain on the susceptible cotton seed Junmian 1 was significantly weakened. 【Conclusion】 The VDG1-specific fragment of high virulent strain SCF73 plays an important role in the pathogenesis of Verticillium dahliae.