核盘菌几丁质酶基因家族分析与表达特性研究

核盘菌菌核以子实体形式萌发是作物菌核病病害循环中关键性的一环,研究菌核子实体萌发分子机理将为菌核病的安全控制提供线索.该研究通过生物信息学方法对核盘菌几丁质酶基因家族进行分析,并利用实时荧光RT-PCR对其在菌核子实体萌发阶段的表达进行探讨.生物信息学分析表明核盘菌中共有12个基因编码假定的几丁质酶,它们均具有GH18结构域,部分蛋白还具有几丁质结合结构域和纤维素结构域;除SS1G_11212外其余蛋白均为亲水性蛋白;亚细胞定位预测表明其中10个假定几丁质酶位于胞外,其余2个分别位于细胞核和细胞质中.通过构建系统发育树分析发现假定几丁质酶可以分为2大类,其中3个与酵母几丁质酶CTS1归为一类,其余9个与CTS2归为另一类.除SS1G_00773外,其余11个几丁质酶基因在核盘菌菌核子实体萌发过程中表达量均有变化,推测几丁质酶家族蛋白可能参与核盘菌菌核子实体萌发过程.

Characterization and Expression Analysis of Chitinase Family Genes in Sclerotinia sclerotiorum

The carpogenic germination of sclerotia for Sclerotinia sclerotiorum is a key step of crop sclerotiniose infection cycle. Studying the molecular mechanism involved in the carpogenic germination of scleortia will provide clues to control the sclerotiniose safely. In this study, chitinase family proteins of S. sclerotiorum were analyzed with the bioinformation approach, and the expression levels of chitinase genes during the carpogenic germination of sclerotia were determined with RT-PCR method. Bioinformatics analysis showed that 12 genes were predicted to encode chitinase in S. sclerotiorum. All of them had GH18 domains and some also had a chitin-binding domain and a cellulose-binding domain. All the chitinases were hydrophilic except SS1G_11212. Ten chitinases were predicted to be located outside the cell, and the others were located in the nucleus cytoplasm. Phylogenetic tree analysis showed that the 12 chitinases could be divided into two categories, of which 3 with yeast chitinase CTS1 were clustered together and the rest with CTS2 were clustered together. The expression level of the 11 chitinase genes changed during the carpogenic germination of sclerotia, except SS1G_00773, suggesting that chitinase family proteins are involved in the carpogenic germination of sclerotia for S. sclerotiorum.