菊芋果聚糖合成关键基因1-SST克隆及序列分析

Cloning and Sequence Analysis of Sucrose:Sucrose-1-fructosyltransferase(1~SST)Gene from Helianthus tuberosus L.

果聚糖是菊芋的主要贮藏物质,其代谢与产量形成和逆境适应性密切相关。为了解菊芋果聚糖合成代谢的机制,本研究以‘青芋1号’为研究对象,利用同源克隆方法,对果聚糖合成关键基因1-SST克隆及序列分析。结果表明,1-SST基因全长为3 925 bp,CDS大小为1 890 bp,由5个内含子和6个外显子组成。经生物信息学分析,预测1-SST蛋白分子量70 934.40 Da,等电点5.10,有两个属于糖基水解酶32家族的保守区,属于亲水性蛋白,以延伸结构(24.48%)和无规则卷曲(56.76%)为主要二级结构,在质膜外行使功能。系统进化分析表明,菊芋1-SST基因与向日葵遗传距离最近,与龙舌兰等不同科不同属的植物进化距离较远。本研究基于对菊芋中调控果聚糖合成代谢1-SST基因的克隆与生物信息学分析,为高等植物果聚糖代谢途径研究奠定一定的理论基础。

Fructose is the main storage material of Jerusalem artichoke, and its metabolism is closely related to yield formation and adaptability to stress. In order to understand the mechanism of the synthesis and metabolism of Jerusalem artichoke fructan, this study used ’Qinglan No.1’ as the research object, and used the TA cloning method to clone and sequence the key gene 1-SST of fructan synthesis. The results showed that the 1-SST gene was 3 925 bp in length and the CDS was 1 890 bp in length, consisting of 5 introns and 6 exons. Bioinformatics analysis predicted that the 1-SST protein had a molecular weight of 70 934.40 Da and an isoelectric point of 5.10. There were two conserved regions belonging to the glycosyl hydrolase 32 family, belonging to the hydrophilic protein, with an extended structure(24.48%), and none. Regular curl(56.76%) is the primary secondary structure that functions outside the plasma membrane. Phylogenetic analysis showed that the 1-SST gene was the closest genetic distance to sunflower, and it was far away from the evolution of plants of different genus such as agave. This study is based on the cloning and bioinformatics analysis of the 1-SST gene in the regulation of fructan anabolism in Jerusalem artichoke, which lays a theoretical foundation for the study of the metabolism pathway of higher plant fructan.