香蕉枯萎病菌2种细胞壁降解酶酶活性平板检测方法

摘要

This paper reports a plate assay to detect activities of polygalacturonase and cellulase secreted by Fusarium oxysporum f.sp.cubense (FOC),which is the most destructive pathogen of banana.The optimum cultural conditions for the polygalacturonase production were using pectin as induced substrate to inoculate with 1 × 104 mL-1 conidia of FOC and after being cultured for 3 days.The optimal temperature of polygalacturonase activity was 37 ℃.The optimum cultural conditions for cellulase production were using carboxymethyl cellulose (CMC) as induced substrate to inoculate with 1 × 105 mL-1 conidia of FOC in inducing medium after being cultured for 3 days.The optimal temperature of cellulase activity was 37℃.Based on the method,two mutants with impaired polygalacturonase and cellulose activity were attained through screening virulence-reduced mutants of FOC.%以病原真菌香蕉枯萎病菌4号生理小种为材料,建立了多聚半乳糖醛酸酶和纤维素酶的平板检测方法.多聚半乳糖醛酸酶的最佳产酶和检测条件为:诱导底物为果胶,接种孢子终浓度为1×104 mL-1,培养时间为3 d.37℃时检测的多聚半乳糖醛酸酶活性最大；纤维素酶的最佳产酶和检测条件为:诱导底物为羧甲基纤维素,接种孢子终浓度为1×105 mL-1,培养时间为3d,37℃时检测的纤维素酶活性最大.在此基础上,筛选已获得的香蕉枯萎病菌4号生理小种致病力减弱突变体,获得了2株多聚半乳糖醛酸酶和纤维素酶酶活性显著降低的致病突变体.