Fang Ting, Peng Yuan, Rao Ya, Li Shenghao, Zeng Lihui
College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Institute of Genetics and Breeding in Horticultural Plants, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Plants (Basel). 2020 Mar 8;9(3):342. doi: 10.3390/plants9030342.
Carbohydrates are nutrients and important signal molecules in higher plants. Sugar transporters (ST) play important role not only in long-distance transport of sugar, but also in sugar accumulations in sink cells. Longan ( L.) is one of the most important commercial tropical/subtropical evergreen fruit species in Southeast Asia. In this study, a total of 52 longan sugar transporter (DlST) genes were identified and they were divided into eight clades according to phylogenetic analysis. Out of these 52 DlST genes, many plant hormones (e.g., MeJA and gibberellin), abiotic (e.g., cold and drought), and biotic stress responsive element exist in their promoter region. Gene structure analysis exhibited that each of the clades have closely associated gene architectural features based on similar number or length of exons. The numbers of DlSTs, which exhibited alternative splicing (AS) events, in flower bud is more than that in other tissues. Expression profile analysis revealed that ten DlST members may regulate longan flowerbud differentiation. In silico expression profiles in nine longan organs indicated that some DlST genes were tissue specificity and further qRT-PCR analysis suggested that the transcript level of seven DlSTs (, , , , , and ) was consistent with sugar accumulation in fruit, indicating that they might be involved in sugar accumulations during longan fruit development. Our findings will contribute to a better understanding of sugar transporters in woody plant.
碳水化合物是高等植物中的营养物质和重要信号分子。糖转运蛋白（ST）不仅在糖的长距离运输中起重要作用，而且在库细胞中的糖积累中也起重要作用。龙眼是东南亚最重要的商业热带/亚热带常绿果树种之一。在本研究中，共鉴定出52个龙眼糖转运蛋白（DlST）基因，并根据系统发育分析将它们分为8个分支。在这52个DlST基因中，许多植物激素（如茉莉酸甲酯和赤霉素）、非生物（如寒冷和干旱）和生物胁迫响应元件存在于它们的启动子区域。基因结构分析表明，每个分支基于外显子的相似数量或长度具有紧密相关的基因结构特征。在花芽中表现出可变剪接（AS）事件的DlST数量多于其他组织。表达谱分析表明，10个DlST成员可能调控龙眼花芽分化。九个龙眼器官的电子表达谱表明，一些DlST基因具有组织特异性，进一步的qRT-PCR分析表明，七个DlST（、、、、、和）的转录水平与果实中的糖积累一致，表明它们可能参与龙眼果实发育过程中的糖积累。我们的研究结果将有助于更好地理解木本植物中的糖转运蛋白。
