过表达橡胶草糖转运蛋白TkSWEET1促进橡胶草的橡胶合成  

Overexpressing TkSWEET1 stimulates natural rubber biosynthesis in rubber dandelion(Taraxacum kok-saghyz)

作　　者：张宇豪 张义 徐梦毫[1] 杨雪 邢剑锋 唐朝荣 王将 ZHANG Yuhao;ZHANG Yi;XU Menghao;YANG Xue;XING Jianfeng;TANG Chaorong;WANG Jiang(school of Tropical Agriculture and Forestry of Hainan University,Haikou 570228,China;Sanya Institute of Breeding and Multiplication of Hainan University,Sanya,Hainan 572025,China)

机构地区：[1]海南大学热带农林学院,海口570228 [2]海南大学三亚南繁研究院,海南三亚572025

出　　处：《植物生理学报》2024年第5期879-886,共8页Plant Physiology Journal

基　　金：国家自然科学基金(31825007和32300231);海南省自然科学基金高层次人才项目(321RC1029)。

摘　　要：橡胶草是产胶替代植物,其橡胶产量与库器官中的糖代谢过程密切相关,SWEET糖转运蛋白参与调控糖在库器官的分配。前期研究发现,TkSWEET1具有糖转运活性,并在橡胶草胶乳(乳管的细胞质)中表达量较高。本研究首先通过qPCR检测了TkSWEET1在橡胶草全生育期的时空表达特征,结果表明其在橡胶草中后期的根和胶乳中高表达。本研究还通过乳管特异表达基因(TkREF)的启动子过表达TkSWEET1。三个独立稳定转化株系中,TkSWEET1的表达量均显著高于野生型,但TkSWEET1-GFP融合蛋白并非乳管细胞特异。过表达TkSWEET1显著促进了根的伸长,并有增加根中胶含量和单株胶产量的趋势,而根部可溶性糖的含量、植株生物量并无显著影响。本研究为进一步探究橡胶草糖代谢对天然橡胶生物合成的影响提供参考。Rubber dandelion(Taraxacum kok-saghyz)is an alternative natural rubber crop.Natural rubber biosynthesis in sink tissues depend on sugar metabolisms.SWEET sugar transporter family participates sugar allocation in sink tissues.Previous study reported TkSWEET1 can transport sugars and is highly expressed in latex(cytosol of laticifer cells).Here,the spatial-temporal gene expression pattern of TkSWEET1 throughout the entire growth stages of T.kok-saghyz was investigated using qPCR,and TkSWEET1 was highly expressed in root and latex at mid-/late-developmental stages,respectively.Overexpressing Tk-SWEET1 driven by the promoter of TkREF,a latex-specific gene,was carried out.TkSWEET1 was highly overexpressed in 3 independent transgenic lines,but TksWEET1-GFP was not observed in a laticifer cell-specific manner.Root elongation was significantly increased in TksWEET1 overexpressing lines,and an increasing trend of natural rubber content and yield was observed.By contrast,soluble sugar content and plant biomass were not affected.This study helps to further elucidate the role of sugar metabolism in natural rubber biosynthesis.

关 键 词：橡胶草 SWEET 乳管细胞 过表达 糖转运 橡胶合成 

分 类 号：S576[农业科学—作物学]