光合作用同化物分配供给是果实和种子发育的主要限制因子，增加蔗糖分配转运到果实和种子是增产优质的潜在策略。SWEET（sugar will eventually be exported transporter）是近年来被鉴定较多的一类糖转运蛋白，该蛋白质通过从源叶运输营养物质调控库组织发育，参与植物生长发育以及生物和非生物胁迫反应。SWEET蛋白定位于膜结构，属于MtN3家族，通常包含7个跨膜结构域，其中包含2个MtN3/saliva结构域。随着染色体加倍、片段复制和串联复制等，SWEET基因在物种中得到扩张。SWEET4和SWEET39基因是作物驯化改良过程中选择的关键基因；SWEET9蛋白是蜜腺特异性糖转运蛋白，参与植物蜜腺的进化；SWEET16和SWEET17蛋白参与植物根系生长发育；SWEET11和SWEET15蛋白参与植物种子胚乳填充。本文系统综述了SWEET蛋白的结构、数量、分类、亚细胞定位、成员扩张与进化，分析了SWEET蛋白在叶、茎、根系发育，花药发育，花蜜分泌，种子填充和果实发育等植物生长发育中的功能作用，强调了SWEET蛋白在作物改良中的应用，说明增强源库强度对作物产量提高的可持续性具有重要意义。

The distribution and supply of photosynthetic assimilation products is a major limiting factor of fruit and seed development, and increasing sucrose distribution and transport to fruits and seeds is a potential strategy for increasing yield and quality. SWEET (sugar will eventually be exported transporter) is a type of sugar transporters which have been identified more in recent years, and these proteins regulate sink organ development via transporting nutrients from source leaves and participate in plant growth and development and biotic and abiotic stress response. SWEET proteins are located in membrane structure, belong to MtN3 family, and usually contain seven transmembrane domains, including two MtN3/saliva domains. With chromosome doubling, segmental duplication, tandem duplication, etc., SWEET genes have been expanded in species. SWEET4 and SWEET39 genes are the key genes selected in the domestication and improvement process of crops. SWEET9 protein is a nectaryspecific sugar transporter, which is involved in evolution of plant nectary. SWEET16 and SWEET17 proteins are involved in plant root growth and development. SWEET11 and SWEET15 proteins are involved in plant seed endosperm filling. This paper systematically reviews the structure, number, classification, subcellular localization, and member expansion and evolution of SWEET proteins, analyses functional roles of SWEET proteins in plant growth and development including leaf, stem, and root development, anther development, nectar secretion, seed filling, and fruit development, highlights the application of SWEET proteins in crop improvement, and elucidates the importance of increasing sinksource intensity for the sustainability of crop yield increase.