Emerging Roles of SWEET Sugar Transporters in Plant Development and Abiotic Stress Responses

Sugars are the major source of energy in living organisms and play important roles in osmotic regulation, cell signaling and energy storage. SWEETs (Sugars Will Eventually be Exported Transporters) are the most recent family of sugar transporters that function as uniporters, facilitating the diffusion of sugar molecules across cell membranes. In plants, SWEETs play roles in multiple physiological processes including phloem loading, senescence, pollen nutrition, grain filling, nectar secretion, abiotic (drought, heat, cold, and salinity) and biotic stress regulation. In this review, we summarized the role of SWEET transporters in plant development and abiotic stress. The gene expression dynamics of various SWEET transporters under various abiotic stresses in different plant species are also discussed. Finally, we discuss the utilization of genome editing tools (TALENs and CRISPR/Cas9) to engineer SWEET genes that can facilitate trait improvement. Overall, recent advancements on SWEETs are highlighted, which could be used for crop trait improvement and abiotic stress tolerance.

Automated summary

Sugars are a vital energy source in living organisms and have various functions in osmotic regulation, cell signaling, and energy storage. SWEETs, the newest family of sugar transporters, facilitate the diffusion of sugar molecules across cell membranes. In plants, SWEETs play important roles in processes such as phloem loading, senescence, pollen nutrition, grain filling, and response to abiotic and biotic stress. This review summarizes the functions of SWEET transporters in plant development and abiotic stress, as well as discusses the gene expression dynamics of different SWEET transporters under various abiotic stresses. Additionally, the potential of genome editing tools for improving SWEET genes is explored. Overall, the recent advancements in SWEET research have significant implications for crop improvement and abiotic stress tolerance.