茶树蔗糖转运蛋白(SUTs)基因家族鉴定及组织表达分析

Identification and Tissue Expression Analysis of Sucrose Transporter(SUT)Gene Family in Camellia sinensis

蔗糖转运蛋白(SUTs)是蔗糖转运的主要载体,其运输、装载蔗糖需要消耗能量,在植物光合产物从源到库的转运过程中起关键作用。从茶树品种舒茶早中鉴定获得7个CsSUTs家族成员,对其理化性质、基因结构、亚细胞定位、进化关系、顺式作用元件等展开生物信息学分析。CsSUTs家族蛋白含有一个保守MFS-2结构域,且与拟南芥AtSUCs蛋白的亲缘关系较近,茶树CsSUTs蛋白被聚类在SUTⅠ、Ⅱ和Ⅳ;在STRING在线网站中以拟南芥AtSUCs为模型,推测茶树CsSUTs蛋白与SWEET、SUS、STP蛋白可能存在直接的相互作用关系。对茶树CsSUTs家族基因的启动子区域进行分析,发现其中存在大量与激素响应、非生物胁迫,以及植物生长发育相关的顺式作用元件,推测这些启动子可能受到植物激素、逆境等多种因素的调控,从而影响茶树的生长和发育过程。CsSUTs家族基因在龙井43和舒茶早中的表达模式存在差异,CsSUT6在茶树花中特异性高表达,推测其可能在花器官蔗糖供给、贮藏和分配中发挥重要作用;CsSUT1和CsSUT5在茶树各个器官中均有表达,表明其可能协同参与蔗糖在“源”叶的装载和“库”器官卸载等过程。

Sucrose transporters(SUTs),the main sucrose carriers,consume energy to transport and load sucrose,which play a key role in the transport of plant photosynthetic products from source to sink.In this study,seven members of CsSUTs family were identified from Camellia sinensis‘Shuchazao’by bioinformatics analysis.Their physical and chemical properties,gene structure,subcellular localization,evolutionary relationship and cis-acting elements were analyzed.The identified CsSUT proteins,containing a conserved MFS-2 domain,are closely related to AtSUC proteins in Arabidopsis thaliana,which are clustered in SUTⅠ,ⅡandⅣ.AtSUC proteins of Arabidopsis thaliana were used as a model in the STRING online website to speculate that there might be a direct interaction between CsSUT proteins and SWEET,SUS and STP proteins.Analysis of the promoter regions of the CsSUT family genes in tea plants reveals that there were masses of cis-acting elements related to hormone response,abiotic stress,and plant growth and development.It is speculated that these promoters may be regulated by plant hormones,stress and other factors,thus affecting the growth and development of tea plants.There were differences in the expression patterns of CsSUT family genes in C.sinensis‘Longjing 43’and C.sinensis‘Shuchazao’.CsSUT6 was highly expressed in flowers,suggesting that it may contribute to the supply,storage and distribution of sucrose in floral organs.CsSUT1 and CsSUT5 were highly expressed in various organs of tea plants,indicating that they may synergistically participate in the process of sucrose loading in‘source’leaves and unloading in‘sink’organs.