植物蔗糖合酶家族基因鉴定及序列和进化分析

Identification, Sequence Analysis and Evolutionary Inference of Plant Sucrose Synthase Family Genes

蔗糖合酶(SUS)是植物中广泛存在的一种糖基转移酶,而蔗糖磷酸合成酶(SPS)是高等植物体内控制蔗糖合成的关键酶之一。对于SUS与SPS是否来自同一源头,其序列是否存在同源区域,以及其进化路径等,尚未见相关报道。本研究针对这两个酶的基因序列,鉴定得到其保守结构域,在此基础上对相关基因进行了全面鉴定,从而构建了其进化树。从序列上看,这两种酶(SUS,SPS)具有一定的同源性。通过结构域鉴定,SPS1基因的蛋白序列中鉴定得到3个结构域,而从SUS1中鉴定得到2个结构域;由以上结果可知,SUS和SPS属于同一基因家族。通过进化树构建,SUS、SPS家族的基因聚成了两个显著独立枝。因此,SUS、SPS分别属于一个独立的亚家族。本研究为植物糖代谢相关研究提供了基因靶标,为蔗糖代谢和转运相关基因进化机制的研究提供了基础。

Sucrose synthase （SUS） is a widely existing sugar-base transfer enzyme in plants, and sucrose phosphate synthase （SPS） is one of the key enzymes to control sucrose synthesis in higher plants. No studies have been reported to explain whether SUS and SPS come from the same source, whether their sequences have homologous regions, and how they evolved. In this study, the gene sequences and the conserved domains of these two enzymes were identified, on basis of which a comprehensive identification of related genes was carried out, and its evolutionary tree was constructed. From the sequence, the two enzymes （SUS, SPS） had certain homology. Through the identifi- cation of structure domain, 3 domains were identified in the protein sequence of SPS1 gene, and 2 domains were identified from SUS 1. The above results indicated that SUS and SPS belonged to the same gene family. Through the evolution tree construction, it was found that the genes in the SUS and the SPS family gathered to form two distinct independent branches. Therefore, the SUS and the SPS belonged to independent subfamilies. This study provided a genetic target for the study of plant sugar metabolism, which offered a basis for the study of the mechanism of genetic evolution related to sucrose metabolism and transport related genes.