Fakher Beenish, Jakada Bello Hassan, Greaves Joseph G, Wang Lulu, Niu Xiaoping, Cheng Yan, Zheng Ping, Aslam Mohammad, Qin Yuan, Wang Xiaomei
Guangxi Key Lab of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning, China.
Horticulture Research Institute, Guangxi Academy of Agricultural Sciences, Nanning Investigation Station of South Subtropical Fruit Trees, Ministry of Agriculture, Nanning, China.
Front Plant Sci. 2022 Oct 24;13:964897. doi: 10.3389/fpls.2022.964897. eCollection 2022.
In plants, sugars are required for several essential functions, including growth, storage, signaling, defense and reproduction. Sugar transporters carry out the controlled movement of sugars from source (leaves) to sink (fruits and roots) tissues and determine the overall development of the plant. Various types of sugar transporter families have been described in plants, including sucrose transporters (SUC/SUT), monosaccharide transporter (MST) and SWEET (from Sugar Will Eventually be Exported Transporters). However, the information about pineapple sugar transporters is minimal. This study systematically identified and classified 45 MST and 4 SUC/SUT genes in the pineapple genome. We found that the expression patterns of sugar transporter genes have a spatiotemporal expression in reproductive and vegetative tissues indicating their pivotal role in reproductive growth and development. Besides, different families of sugar transporters have a diel expression pattern in photosynthetic and non-photosynthetic tissues displaying circadian rhythm associated participation of sugar transporters in the CAM pathway. Moreover, regulation of the stress-related sugar transporters during cold stress indicates their contribution to cold tolerance in pineapple. Heterologous expression (yeast complementation assays) of sugar transporters in a mutant yeast strain suggested that SUT1/2 have the ability to transport sucrose, and STP13, STP26, pGlcT-L2 and TMT4 are able to transport glucose, whereas SWEET11/13 transport both sucrose and fructose. The information provided here would help researchers further explore the underlying molecular mechanism involved in the sugar metabolism of pineapple.
在植物中，糖类对于多种基本功能至关重要，包括生长、储存、信号传导、防御和繁殖。糖转运蛋白负责糖类从源组织（叶片）到库组织（果实和根）的受控运输，并决定植物的整体发育。植物中已描述了多种类型的糖转运蛋白家族，包括蔗糖转运蛋白（SUC/SUT）、单糖转运蛋白（MST）和SWEET（源自“糖最终会被输出转运蛋白”）。然而，关于菠萝糖转运蛋白的信息极少。本研究系统地鉴定并分类了菠萝基因组中的45个MST基因和4个SUC/SUT基因。我们发现糖转运蛋白基因的表达模式在生殖组织和营养组织中具有时空表达，表明它们在生殖生长和发育中起关键作用。此外，不同家族的糖转运蛋白在光合组织和非光合组织中具有昼夜表达模式，显示出糖转运蛋白在景天酸代谢途径中的昼夜节律相关参与。此外，冷胁迫期间与胁迫相关的糖转运蛋白的调控表明它们对菠萝耐寒性的贡献。在突变酵母菌株中糖转运蛋白的异源表达（酵母互补试验）表明，SUT1/2具有运输蔗糖的能力，STP13、STP26、pGlcT-L2和TMT4能够运输葡萄糖，而SWEET11/13既能运输蔗糖又能运输果糖。此处提供的信息将有助于研究人员进一步探索菠萝糖代谢所涉及的潜在分子机制。
