松材线虫纤维素酶的活性鉴定和病理分析(英文)  

Activity Characterization and Pathology Analysis of Cellulase from Bursaphelenchus xylophilus

作　　者：张奇[1] 高智慧[2] 慈欣培[2] 白芳[1] 张楚菁[3] 王永波[3] 王金成[3] 白钢[1,2] 

机构地区：[1]南开大学药学院,天津300071 [2]南开大学生命科学学院,天津300071 [3]天津市出入境检验检疫局,天津300457

出　　处：《南开大学学报（自然科学版）》2009年第5期92-98,共7页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：Natural ScienceFoundation of Tianjin,China(08JCYBJC04400)

摘　　要：分别选取了不同来源的三株松材线虫,对其可能的致病因子纤维素酶进行了基因克隆,其大小分别为1 159、1 138和1 159bp.随后的同源性分析结果表明这三个基因与已报道纤维素酶基因BX-eng-3具有较高的同源性,仅于含有较多重复序列处存在重复次数的差异,同时,由此获得的亲缘关系的结果与RAPD分析结果一致.对四种纤维素酶进行表达及活性确认表明四种纤维素酶水解纤维素能力相当,即纤维素酶所具有的致病性与酶活力自身无关,而是与其表达量相关,暗示存在差异的基因序列可能是纤维素酶的连接域,不影响酶的活性.选取其中一种纤维素酶BXC10进行松树纤维素水解实验,分别进行扫描电镜观察、还原糖分析和小角X射线衍射分析,结果均表明纤维素酶能有效水解松树纤维素,是重要的松材线虫病的致病因子,进一步为酶学学说提供了理论基础.Bursaphelenchus xylophilus, the pine wood nematode （PWN）, causes pine wilt disease, the most devastating pine tree disease. To investigate how inter-strain PWN differences might affect the pathology of the disease, we cloned PWN cellulase genes from three different nematode strains. The three cellulases were homologous to BX-eng-3, another eellulase, and the sequence identity between strain cellulases was similar to strain relatedness determined by RAPD clustering. For all 4 cellulases, cellulase activity was similar, suggesting that the observed sequence differences are in the cellulase linker region, and the pathogenicity maybe be interrelated with eellulase expressed quantities. Because all four cellulases had similar activities, a pine cellulose hydrolysis experiment was done only with BXC10. Scanning electron microscopy, DNS analysis, and small angle X-ray diffraction all revealed cellulose hydrolysis. These results support the enzyme theory of pine wilt disease pathology, which suggests PWN cellulase was an important pathogenic factor of pine wilt disease.

关 键 词：松材线虫 纤维素酶 病例分析 致病因子 

分 类 号：Q814[生物学—生物工程]