SWEET uniporters – a 2026 update

SWEETs are a family of ancient sugar transporters found in Archaea, Eubacteria, oomycetes, fungi, plants and metazoa. In plants, SWEETs play central roles in carbon allocation from source to sink tissues, as well as reproductive development, response to changes in environmental conditions, and biotic interactions. Recent studies have provided deeper mechanistic insights into SWEET-mediated transport, including substrate specificity, transport selectivity, structural dynamics, and the physiological diversification of family members across species. Emerging evidence highlights roles of SWEETs in symbiotic interactions and microbiome-associated carbon exchange. Given the growing number of recent reviews on SWEET physiology, this update focuses on current challenges and emerging perspectives on SWEET-mediated transport processes, cell-type specificity, functional diversification, the interpretation of overexpression phenotypes, and functions in symbiotic interactions. We also discuss how these insights may be leveraged to optimize carbon partitioning, improve resilience, and enhance crop productivity and biofuel production.