酚类物质对哈密瓜两种主要致腐病原产生的细胞壁降解酶活性的影响

Effect of Phenolis on Cell Wall-degrading Enzyme of Two Main Rot Pathogens from Hami Melon

本研究表明引起哈密瓜采后腐烂的两种主要致腐性病原,匍枝根霉(Rhizopusstolonifer)、半裸镰刀菌(Fusariumsemitecum),在诱导培养基上均能产生多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PME)和纤维素酶(Cellulase)。其中Rhizopusstolonifer所产的这两种果胶酶类多聚半乳糖醛酸酶与果胶甲酯酶的活性均比Fusariumsemitecum所产的多聚半乳糖醛酸酶与果胶甲酯酶的活性高。而F.semitecum所产的纤维素酶活性比R.stolonifer产的酶活高。邻苯二酚、对苯二酚、对羟基苯甲酸丁酯均能明显地降低R.stolonifer与F.semitecum产生多聚半乳糖醛酸酶,果胶甲酯酶与纤维素酶的能力,并且这些酚类物质对这些酶的活性也有明显的抑制作用。培养基中加入1%果胶或1%的羧甲基纤维素钠(CMC),则均能诱导病原菌产酶,且酶活性不同。其中果胶在诱导病原物产生多聚半乳糖醛酸酶、果胶甲酯酶方面特别显著,果胶与CMC在诱导病原菌产纤维素酶方面差别不大。

Two main rot pathogens were carded by of Hami Melon, Rhizopus stolonifer and Fusarium semitecum. They were capable to produce a series of cell wall-degrading enzymes （CWDE） in medium. The results showed that PG and PME from Rhizopus stolonifer showed a higher activity than that from Fusarium semitecum. But F.semitecum was capable to produce some higher Cellulase activity than R. stolonifer. Pyrocatechol, hydroquinone and Buty-p-nydroxy benaxoate all were capable to not only decrease pathogens to produce PG, PME and Cellulase, but also inhibit these enzymes activities. It was found that the CWDE activity （PG, PME, ceUulase） produced by the two pathogens is higher in medium containing 1% pectin than that containing 1% CMC. Pectin was capable to induce the two pathogens to produce great amount of PG and PME, but CMC can not. There is no great difference for pectin and CMC to induce the two pathogens to produce cellulase.