具有抗农作物病原真菌活性的链霉菌IIR21菌株中attB位点的分析

Analysis of att B Site in Streptomyces sp. IIR21 Resistance to Crop Pathogenic Fungi

以7种农作物病原真菌为指示菌,采用菌块法和杯碟法测定了链霉菌IIR21菌株次级代谢产物的抗农作物病原真菌活性,用PCR方法扩增了链霉菌IIR21菌株的att B的序列,并进行了生物信息学分析.结果表明:链霉菌IIR21菌株对稻瘟病菌、立枯丝核病菌具有较强的抑菌活性;链霉菌IIR21菌株的att B位点序列长269 bp,它与Streptomyces natalensis的att B位点核心区域的序列的相似度最高,达到92%,具有发生交换的核心区域5'-TT.含有ΦC31att P位点的整合型质粒p SET152可通过att P位点与链霉菌IIR21菌株的染色体上的att B位点发生位点特异性重组.

The antifungal activity of the secondary metabolite of Streptomyces sp.IIR21 strain was detected through the agar block method and cylinder plate method with seven crop pathogenic fungi as indicators .The attB site sequence for site specific recombination was cloned by PCR and analyzed by bioinformatics .The results indicated that Streptomyces sp.IIR21 strain exhibited much stronger antifungal activity against Magnaporthe grisea and Rhizoctonia solani.The attB site sequence of the Streptomyces sp.IIR21 strain was of a length of 269 bp, and is most similar to the attB site core region of Streptomyces.natalensis, with similarity reaching 92%, and contain the core cross-over region 5′-TT.The integrative plasmid pSET152 including ΦC31 attP site recombined specifically between the attP site in pSET152 and the attB site in the chromosome of Streptomyces sp.IIR21 strain.