细胞壁降解酶在油茶炭疽病菌致病过程中的作用研究

为明确细胞壁降解酶在油茶炭疽病菌致病过程中的作用,本文研究了活体内外炭疽病菌产生的细胞壁降解酶活性及其对叶片的降解情况。结果表明,活体外以羧甲基纤维素钠(CMCNa)为诱导底物,羧甲基纤维素酶(Cx酶)和漆酶活性最高;以柑橘果胶为诱导底物,果胶酶活性最高;以油茶叶为诱导底物,纤维素酶、果胶酶和漆酶可产生较高活力;并且经5种诱导物诱导的酶液对叶片均有降解作用。发病叶片的各部位,以病健交界处细胞壁降解酶活性最高。接种4d后开始发病,其细胞壁降解酶活性迅速增强;6d后滤纸酶(FPA)、β-葡萄糖苷酶和漆酶活性达最大值,分别为4.53、7.44、1.21U/mg;而Cx酶和果胶酶在第8天时酶活性最高,分别为15.79和25.49U/mg;接种10~16d,酶活性比较稳定。上述结果表明,纤维素酶、果胶酶和漆酶在油茶炭疽病菌致病过程中起重要作用。

The role of cell walldegrading enzymes in the pathogenic process of Camellia oleifera disease caused by Colletotrichum gloeosporioides

The research aims to estimate the role of cell wall-degrading enzymes(CWDEs) in the pathogenic process of Camellia oleifera anthracnose caused by Colletotrichum gloeosporioides.CWDEs produced by C.gloeosporioides both in vitro and in vivo were studied.The results showed that,with carboxymethyl cellulose sodium (CMCNa) as the inducer substrate,the activities of carboxymethyl cellulase and laccase were the highest,whereas citrus pectin was the best for pectinase.C.gloeosporioides could produce highly active cellulase,pectinase and laccase induced by C.oleifera leaves,and all enzyme liquids produced by the 5 inducers had degradation activity against leaves.Among each part of the diseased leaves,the activity of the CWDEs along the boundary between diseased and healthy areas was the highest.The activities of the CWDEs rapidly increased 4 days after inoculation when the leave symptoms emerged.The activities of filter paper enzyme (FPA),β-glucosidase and laccase with a maximum value in the 6th day after inoculation,were 4.53 U/mg,7.44 U/mg,and 1.21 U/mg,respectively.But carboxymethyl cellulase(Cx)and pectinase reached at the peak in the 8th day after inoculation.The activities of the CWDEs were very stable from the 10th to 16th days after inoculation.These results demonstrated that cellulase,pectinase and laccase played an important role in the pathogenic processes of C.oleifera anthracnose caused by C.gloeosporioides.