College of Horticulture and Forestry Sciences, Huazhong Agricultural University and Key Laboratory of Horticultural Plant Biology, Ministry of Education, Wuhan 430070, China.
Int J Mol Sci. 2020 May 15;21(10):3524. doi: 10.3390/ijms21103524.
Sugar allocation is based on the source-to-sink and intracellular transport between different organelles, and sugar transporters are usually involved in these processes. Tonoplast sugar transporters (TST) are responsible for transporting sugar into vacuoles; however, the role of TSTs in root growth and the response to abiotic stress is poorly studied. Here, RNA analysis and promoter--glucuronidase staining revealed that a melon TST1 gene () is highly expressed in the roots. The sugar feeding experiment results showed that the expression of in the roots was induced by a relatively high level of sucrose (6%), glucose (3%), and fructose (3%). The ectopic overexpression of in improved the root and shoot growth of seedlings under high exogenous sugar stress. Furthermore, the ectopic expression of promoted the expression of plasma membrane-located sugar transporters. We proposed that CmTST1 plays a key role in importing sugar transport into the vacuoles of roots in response to metabolic demands to maintain cytosolic sugar homeostasis.
糖的分配是基于不同细胞器之间的源到汇和细胞内运输，糖转运蛋白通常参与这些过程。液泡膜糖转运蛋白（TST）负责将糖转运到液泡中；然而，TST 在根生长和对非生物胁迫的响应中的作用还研究得很少。在这里，RNA 分析和启动子-葡糖醛酸酶染色表明，一种甜瓜 TST1 基因（）在根中高度表达。糖喂养实验结果表明，根中 的表达受相对高水平的蔗糖（6%）、葡萄糖（3%）和果糖（3%）诱导。在高外源糖胁迫下，在 中异位过表达 ，促进了幼苗的根和地上部生长。此外， 的异位表达促进了质膜定位糖转运蛋白的表达。我们提出 CmTST1 在响应代谢需求将糖运输到根液泡中以维持细胞溶质糖稳态方面发挥关键作用。
