稠李链霉菌JAU4234代谢产物对水稻纹枯病菌的作用机制

Effect of metabolin from Streptomyces padanus JAU4234 against Rhizoctonia solani

为了明确稠李链霉菌JAU4234菌株在植物病害防治中的实用价值,采用生长速率法、酶活性测定和聚丙烯酰胺凝胶电泳法研究其代谢产物DZP-8对水稻纹枯病菌的作用机制。DZP-8对菌丝生长的抑制作用明显,EC50为1.55μg/mL。随着DZP-8浓度的提高,病菌羧甲基纤维素酶、多聚半乳糖醛酸酶、果胶甲基半乳糖醛酸酶的活性均有不同程度下降,当DZP-8浓度为4.67μg/mL时,3种酶的活性分别为6.76、20.97、21.74 U/mg,较对照显著降低。DZP-8浓度为4.67μg/mL的处理,只可分辨出8条谱带,蛋白质的种类和含量与对照有显著差异。表明DZP-8对纹枯病菌有较强的抑菌活性,其作用机制是抑制菌丝生长、抑制病菌致病因子表达和蛋白质的合成等。

In order to evaluate the potential application of Streptomyces padanus JAU4234 in the biologi- cal control for plant diseases, the action mechanism of DZP-8 （ an active product isolated and purified from the fermentation broth of S. padanus JAU4234） against Rhizoctonia solani was investigated in virtue of the mycelium growth rate quantification, enzyme activity determination, together with the protein anal- ysis by SDS-polyacrylamide gel electrophoresis （SDS-PAGE）. It was found that the DZP-8 had a strong antagonistic action on that of R. solani hyphae, and the EC50 value was 1.55 μg/mL. With the increase of DZP-8 concentration, the activities of the carboxy methyl cellulose enzyme （ Cx ） , polygalacturonase （PG） and pectin methyl galacturonase （PMG） of R. solani were all decreased. When the DZP-8 concen- tration was 4.67 μg/mL, the activities of the above three cell wall degrading enzymes were 6.76, 20.97 and 21.74 U/mg, respectively, which were all significantly lower than those of control group. Fur- thermore, soluble mycelium proteins only displayed a pattern of 8 protein bands under 4.67 μg/mL of DZP-8, in which the number of protein bands showed a significant difference to the control group. Ac- cording to the above results, it could be concluded that the significantly inhibitory effect of DZP-8 onR. solani was due to the integrative action of DZP-8 on the mycelial growth, pathogenic factor expression and protein synthesis.