辣椒CaTPS8基因克隆与表达分析

Cloning and Expression Analysis of CaTPS8 Gene in Capsicum annuum

海藻糖-6-磷酸合酶(Trehalose-6-phosphate synthase,TPS)在植物非生物胁迫响应中起着重要的调控作用。以辣椒品种‘强丰101’为材料,对CaTPS8基因进行克隆和表达分析。结果表明,该基因CDS的完整开放阅读框为2553 bp,编码850个氨基酸。生物信息学分析发现,CaTPS8蛋白的分子质量为96 ku,理论等电点为5.65,不稳定系数为48.09,推测为不稳定蛋白。蛋白结构预测显示CaTPS8蛋白包含Glyco_transf_20和GT20_TPS两个保守结构域,属于亲水性蛋白,没有跨膜结构和信号肽序列。二级、三级结构预测表明该蛋白的结构主要为α-螺旋和无规则卷曲。系统进化关系分析表明,CaTPS8蛋白与马铃薯和番茄的同源性最高,其相似度分别为87.78%和86.92%,与高粱的同源序列相似度最低,为64.76%。实时荧光定量PCR分析表明,CaTPS8基因在辣椒花中表达量最高。同时,CaTPS8基因的表达受到低温的诱导,在处理3 h时相对表达量最高,约为对照的25倍。此外,IAA、ABA、SA、GA 3和MeJA处理能够抑制CaTPS8基因的表达。研究结果为进一步阐明CaTPS8基因响应辣椒非生物胁迫的分子机理奠定基础。

Trehalose-6-phosphate synthase(TPS)plays an important role in response to abiotic stresses in plants.In this study,the CaTPS8 gene was cloned in a Capsicum annuum L.variety‘Qiangfeng 101’and analyzed by informatics.In addition,the expressing model of CaTPS8 was analyzed by quantitative real-time PCR method.The results showed that the complete open reading frame of CaTPS8 was 2553 bp,encoding 850 amino acids.Bioinformatics analysis showed that the relative molecular mass of CaTPS8 protein was 96 ku,the theoretical isoelectric point was 5.65,and instability coefficient was 48.09,which suggested that CaTPS8 protein should be an unstable protein.The CaTPS8 protein was comprised of two conserved domains,Glyco_transf_20 and GT20_TPS,and classed to hydrophilic protein without protein transmembrane structure and signal peptide sequence.The prediction of secondary and tertiary structure indicated that the structure of CaTPS8 protein was mainly composed ofαhelix and random curl.Phylogenetic analysis manifested that the CaTPS8 protein had the highest homology with potato and tomato,with the similarity of 87.78%and 86.92%,respectively,but the homology with sorghum was the lowest,with a value of 64.76%.Tissue specific expression revealed that the relative expression of CaTPS8 was highest in flowers compared with other tissues.In addition,the expression of CaTPS8 gene was induced by low temperature,and the relative expression of CaTPS8 gene peaked at three hours after treatment,which was about 25 times than that of the control.However,IAA,ABA,SA,GA 3 and MeJA treatments were able to suppress the expression of CaTPS8 to varying degrees.This study laid a foundation for further elucidating the molecular mechanism of CaTPS8 in response to abiotic stress in Capsicum annuum L..