玉米大斑病菌StCHS6的基因结构及表达规律分析

The Structure and Expression Pattern Analysis of StCHS6 Gene in Setosphaeria turcica

为了阐明玉米大斑病菌几丁质合成酶基因StCHS6在病菌生长发育及致病过程中的作用,克隆并解析了该基因及其编码蛋白的结构特征,明确了该基因在病菌生长发育过程中的表达模式。在玉米大斑病菌1号小种菌株01-23中克隆StCHS6,利用生物信息学手段分析该基因的结构特征,并利用已有的病菌重要发育阶段的RNA-Seq数据库信息,明确该基因的表达模式。结果发现,StCHS6位于病菌基因组scaffold1:2066293-2069876(-)的位置,基因全长为3 584 bp,含有4个内含子和5个外显子;CDS序列大小为2 703 bp,编码900个氨基酸,脂肪指数为81.86,亲水性平均值为-0.178,等电点(PI)为8.36,不稳定指数为36.94,属于碱性稳定型蛋白;保守结构域分析表明,StCHS6蛋白含有几丁质合成酶催化结构域Chitinsynth1和多个跨膜结构域;亚细胞定位分析推测该蛋白定位于细胞膜上;RNA-Seq数据分析表明,StCHS6在菌丝、分生孢子、芽管、附着胞和侵入钉5个发育时期均有表达,但其表达量有所差异。以芽管时期的表达量为1,菌丝、分生孢子、附着胞和侵入钉时期的表达量分别为芽管时期的3.80,4.97,3.40,2.60倍。为阐明玉米大斑病菌StCHS6的基因结构特征、表达模式及功能奠定了基础。

In order to clarify the functions of chitin synthase gene StCHS6 in the growth, development and pathogenic process of Setosphaeria turcica, the StCHS6 gene was cloned from strain 01-23. The bioinformatics methods were used to analyze the structure characteristics of the gene and its coding protein, and the expression patterns of the gene during key pathogenic developmental periods were elucidated based on the RNA-Seq data. The results showed that StCHS6 was located at scaffold1:2066293-2069876(-) of the pathogen, and the full length of the gene was 3 584 bp, containing 4 introns and 5 exons. The CDS sequence of the gene was 2 703 bp in size, encoding 900 amino acids, with a fat index of 81.86, a hydrophilic average of-0.178, an isoelectric point(PI) of 8.36, and an instability index of 36.94, which was proved to be an alkaline stable protein. The conserved domain analysis indicated that the StCHS6 protein contained the typical chitin synthase catalytic domain Chitinsynth1 and multiple transmembrane domains. Simultaneously, the protein was presumed to be localized on the cell membrane by subcellular localization analysis. RNA-Seq data analysis showed that StCHS6 was expressed in hypha, conidium, germ tube, appressorium and penetration peg, though their expression levels were different. The expression levels of StCHS6 in hypha, conidium, appressorium and penetration peg were 3.80, 4.97, 3.40 and 2.60 times higher than that in germ tube, respectively. The analysis of structural characteristics and expression pattern of StCHS6 laid the foundation for elucidating the function of this gene in future research.