番茄、拟南芥和葡萄中同型半胱氨酸S-甲基转移酶基因家族功能研究

同型半胱氨酸S-甲基转移酶（homocysteine S-methyltransferase,HMT）普遍存在于被子植物中，在植物合成甲硫氨酸过程中起着重要作用，其在拟南芥中的功能已有所研究，但该家族在其他植物中的功能尚不清楚。本文通过同源比对，获取番茄、拟南芥和葡萄中共8个HMT家族基因的信息，通过系统进化树分析，发现8个HMT蛋白形成2个分支；利用蛋白motif分析、蛋白结构域分析、基因外显子内含子结构分析，发现HMT蛋白在进化上较为保守。通过对拟南芥在非生物胁迫条件下HMT家族基因的表达水平进行分析，发现多个AtHMT基因对非生物胁迫尤其是冷胁迫、盐胁迫、干旱胁迫产生应答，表明HMT家族基因在非生物胁迫应答中的调控作用。另外，通过对番茄各组织在发育的各个阶段中HMT基因进行表达量分析，发现HMT基因可能在番茄种子发育、开花、果实成熟方面发挥作用。综上，本文对番茄、拟南芥和葡萄中HMT基因家族的生物信息学分析及基因表达数据进行了挖掘，对深入研究HMT基因在番茄、拟南芥和葡萄中的作用具有重要意义。

Study on the function of homocysteine S-methyltransferase gene Family in Tomato, Arabidopsis thaliana and grape

Homocysteine S-methyltransferase (HMT) is ubiquitous in angiosperms, and plays an important role in the synthesis of methionine in plants. Its function in Arabidopsis thaliana has been studied. But the function of the family in grapes is unclear. In this paper, we obtained the information of 8 HMT genes in tomato, Arabidopsis and grape by homology comparison. Phylogenetic tree analysis revealed that 8 HMT proteins formed 2 branches. HMT was found to be evolutionarily conserved by protein motif analysis, protein domain analysis and gene exon intron structure analysis. By analyzing the expression level of HMT family genes in Arabidopsis thaliana under abiotic stress, it was found that several AtHMT genes responded to abiotic stress, especially cold stress, salt stress and drought stress, indicating the regulatory role of HMT family genes in abiotic stress response. In addition, by analyzing the expression level of HMT gene in tomato tissues at different stages of development, we found that HMT gene may play a role in tomato seed development, flowering and fruit ripening. In conclusion, bioinformatics analysis and gene expression data of HMT gene families in tomato, Arabidopsis and grape were mined in this paper, which is of great significance for further study on the role of HMT gene in tomato, Arabidopsis thaliana and grape.