牡丹蔗糖转运蛋白基因PsSUT1的功能研究

Functional study of sucrose transporter gene PsSUT1 in peony

蔗糖转运蛋白属于MFS家族,该家族是已知最大的转运体家族。本研究采用“TA”克隆技术,从‘洛阳红’牡丹中得到牡丹蔗糖转运蛋白基因PsSUT1,基因序列全长为1846 bp,包含1557 bp的开放阅读框,编码519个氨基酸。进化树分析显示该基因序列在进化过程中是保守的。蔗糖转运活性试验表明PsSUT1的表达使SUSY7/ura3酵母菌株能够在蔗糖为唯一碳源的培养基上生长,说明PsSUT1编码的蛋白具有蔗糖转运活性。亚细胞定位试验结果表明该蛋白定位于细胞膜。将PsSUT1基因异源转化拟南芥,结果表明PsSUT1转基因阳性苗与野生型拟南芥相比,地上部分干重平均增加了46.35%,株高增加了50.44%,种荚数增加了40.54%;拟南芥蔗糖耐受性检测中,PsSUT1转基因植株生长正常,根系明显比野生型拟南芥植株长,叶片发育也正常,没有花青素积累。本研究为改善盆栽牡丹生长与发育状况提供分子生物学方面的理论依据和技术支撑。

Sucrose transporters belong to the MFS family,which is the largest known family of transporters.In this study,TA cloning technology was used to obtain the peony sucrose transporter gene PsSUT1 from Luoyanghong peony.The full-length gene sequence is 1846 bp,including an open reading frame of 1557 bp,encoding 519 amino acids.Phylogenetic tree analysis showed that the gene sequence was conserved during evolution.The sucrose transport activity assay showed that the expression of PsSUT1 enabled the SUSY7/ura3 yeast strain to grow on the medium with sucrose as the sole carbon source,indicating that the protein encoded by PsSUT1 has sucrose transport activity.The results of subcellular localization assay showed that the protein was localized to the cell membrane.The PsSUT1 gene was heterologously transformed into Arabidopsis,and the results showed that compared with wild-type Arabidopsis,the PsSUT1 transgenic positive seedlings increased the average dry weight of the aerial parts by 46.35%,the plant height by 50.44%,and the number of seed pods by 40.54%;In the Arabidopsis sucrose tolerance test,PsSUT1 transgenic plants grew normally,with significantly longer root systems than wild-type Arabidopsis plants,and normal leaf development without anthocyanin accumulation.This study provides theoretical evidence and technical support in molecular biology for improving the growth and development of potted peony.