摘要
葡萄酸腐病近年来在中国主要葡萄产区发生普遍而严重,造成葡萄近成熟期果穗大量腐烂,直接影响葡萄的产量和质量。【目的】为了明确引起葡萄酸腐病菌的致病机制,对一株强致病性菌株sf-19(Hanseniaspora uvarum)进行细胞壁降解酶及其致病作用的研究。【方法】采用紫外分光光度计法和3,5-二硝基水杨酸法(DNS)测定该病原菌产生细胞壁降解酶的种类和活性。【结果】结果发现:菌株sf-19可以在诱导培养基上产生多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、纤维素酶(Cx)、果胶甲基反式消除酶(PMTE)和多聚半乳糖醛酸反式消除酶(PGTE),其中,PG、PMG和Cx的活性较高,且最适培养时间分别为6、4、2d,最适宜产酶pH为5。另外,菌株sf-19的菌悬液及其产生的细胞壁降解酶可引起葡萄果实腐烂,扫描电镜观察可见葡萄果皮内侧的组织和结构出现空洞及崩解,但果皮表面无明显组织和结构的变化。【结论】结果表明Hanseniaspora uvarum产生的细胞壁降解酶是引起果实腐烂的重要原因之一,且符合其不能直接侵入的特性。
Grape sour rot became one of the most serious diseases and has been widespread in main grape producing areas in China in recent years.It attacked ripening grape berries and reduced grape yield and quality.In order to reveal the pathogenic mechanism,agrape sour rot pathogen,strain sf-19(Hanseniaspora uvarum),isolated from diseased fruits of grape sour rot,was studied in terms of the activities,production condition and pathogenicity of its cell wall degrading enzymes.The types and activity of CWDEs produced by sf-19 were analyzed by the 3,5-two nitro salicylic acid method(DNS)and ultraviolet spectrophotometer method.The results showed that sf-19 could produce polygalacturonase(PG),pectin methylgalacturonase(PMG),celluase(Cx),pectin methyl trans enzyme(PMTE)and polygalacturonic acid transeliminase(PGTE)in induced culture media,and PG,PMG and Cx had strong activities.The optimum culture pH was 5,and the highest activity of PG,PMG and Cx appeared at 6d,4dand 2d,respectively.In addition,both suspension of strain sf-19 and its CWDEs could cause grape fruit to rot.Internal tissue disintegration and external tissue integrity of grape peel was observed using a scanning electron microscope.These result indicated that CWDEs of H.uvarum was one of the important reasons causing fruit decay,but it could not break the upper epidermis of the fruit,which is consistent with the characteristics of the pathogen.
出处
《北京农学院学报》
2016年第1期33-37,共5页
Journal of Beijing University of Agriculture
基金
北京市自然科学基金(6132008)
现代农业产业技术体系建设专项资金资助(CARS-30-bc-2)
