哥斯达黎加链霉菌A-m1的促生作用及解析

Analysis of the Growth Promoting Effect and Mechanism of Streptomyces costaricanus A-m1

为了探究哥斯达黎加链霉菌菌株A-m1对植物的潜在促生作用及机制,首先利用番茄苗生长分析菌株A-m1具有的促生作用,然后对菌株A-m1的全基因组序列进行比对分析,解析促生作用相关的遗传基础,最后使用沙尔科夫斯基反应法(Salkowski)测定菌株A-m1产吲哚乙酸(IAA)能力,铬天青(CAS)法验证产铁载体活性。结果表明,菌株A-m1对番茄幼苗表现出显著促生作用,促生作用与菌体添加量呈正相关,菌株固体发酵产物在基质中添加量为40 g/kg时,番茄植株的叶长、株高、整株鲜质量、整株干质量、根干质量和茎秆直径分别增加了107.1%,70.7%,439.9%,427.4%,473.4%和78.7%。菌株A-m1基因组包含有促进植物生长相关的生长素、细胞分裂素、铁载体、ACC脱氨酶、植酸酶、磷酸酶、固氮酶基因;后续的生化分析进一步证明,菌株A-m1具有合成IAA和铁载体的能力。番茄幼苗的生长证实了菌株A-m1的促生作用,基因组分析和生化验证解析了促生的机制,为该菌株的进一步开发利用奠定了基础。

The growth promoting effect and mechanism of Streptomyces costaricanus strain A-m1 on tomato seedlings were analyzed.At first,the experiment clarified the effect of adding the solid fermentation product of strain A-m1 to the substrate on the growth of tomato seedlings.Then,the whole genome sequences of strain A-m1 were compared to analyze the genetic basis related to growth promotion.Finally,the ability of strain A-m1 to produce indoleacetic acid(IAA)and siderophore was measured by Salkowski method and chromazurol(CAS)method.The results showed that the strain A-m1 significantly promoted the growth of tomato seedlings.The growth-promoting effect was positively related to the amount of Streptomyces costaricanus added.When the content of the solid fermentation product in the substrate was 40 g/kg,the leaf length,plant height,whole plant fresh quality,whole plant dry quality,root dry quality and stem diameter of tomato plants increased by 107.1%,70.7%,439.9%,427.4%,473.4%and 78.7%,respectively.Genome analysis showed that the strain A-m1 had the genes related to auxin,cytokinin,siderophore,ACC deaminase,phytase,phosphatase and nitrogenase,which could promote plant growth;Biochemical analysis of the strain A-m1 further validated the ability to synthesize IAA and siderophore.Growth of tomato seedling confirmed the promoting effect of the strain A-m1,and genome analysis and biochemical verification further clarified the growth-promoting mechanism of the strain,which laid the foundation for further development and utilization of the strain.