番茄SlMYBL基因的克隆、生物信息学及表达特性分析

Cloning,Bioinformatics and Expression Analysis of SlMYBL Gene in Tomato

MYB转录因子构成了植物体内最大的转录因子家族之一,参与植物生长发育和代谢,是一种重要的转录因子。根据NCBI数据库登录的番茄序列,通过RT-PCR方法从野生型番茄AC++中克隆得到全长为1 630 bp基因片段,生物信息学分析表明,该基因ORF为1 245 bp,编码414个氨基酸,该编码蛋白有保守的DNA结合域:MYB-like、C-末端和多个磷酸化位点,主要定位于线粒体基质和细胞质中,根据其结构域该基因命名为SlMYBL。二级结构预测显示SlMYBL蛋白含有26.33%的α螺旋,65.46%的无规则卷曲和6.28%的延伸链及1.93%的β折叠。表达模式分析表明,SlMYBL在成熟叶、茎及萼片中表达量较高。荧光定量PCR分析表明SlMYBL基因表达量受外源激素IAA、ABA等的诱导。非生物胁迫结果表明,在高温、低温、伤害和盐处理中该基因表达也受到不同程度的诱导。该实验结果为进一步研究SlMYBL基因在番茄生长发育过程中的功能奠定了基础。

MYB proteins comprise one of the largest families of transcription factors in plants and are involved in plant growth and metabolism. According to the tomato sequences in the NCBI database,a 1 630 bp DNA fragment was cloned by RT-PCR from wild-type tomato AC＋ ＋,and its opening reading-frame（ORF） was 1 245 bp,encoding 414 amino acids with a conservative DNA binding domain： MYB-like,C-terminal end and multiple phosphorylation sites,named SlMYBL. Bioinformatics analysis indicated that SlMYBL protein might be localized in the mitochondrial matrix and cytoplasm. Secondary structure prediction suggested that SlMYBL protein contains 26. 33% alpha helix,65. 46% of no rules curl and 6. 28% of the extended chain and 1. 93%beta collapse. Real-time fluorescent quantitative PCR analysis showed that SlMYBL was highly expressed in mature leaves,stems,and sepals comparing with other tissues,and was induced by exogenous ethylene precursor IAA, ABA. In addition, the expression of SlMYBL was also induced under high and low temperatures,injury and salt stress. These results lay a foundation for further study on function of the SlMYBL gene in the process of growth and development of tomato.