Trehalose 6-phosphate - a central regulator at the crossroads of sugar signalling, metabolism, and development

In mammals, blood sugar levels are tightly controlled by two hormones: insulin and glucagon. In flowering plants, a comparable regulatory mechanism exists, mediated by the sugar-signalling molecule trehalose 6-phosphate (Tre6P). Similar to insulin, Tre6P functions as a signal and negative feedback regulator of sucrose, the main transport sugar in vascular plants. In the model plant Arabidopsis thaliana and likely all other angiosperms, Tre6P is predominantly synthesized in the vasculature, an ideal position to integrate systemic sugar status with whole-plant developmental decision-making. Genes encoding components of Tre6P dephosphorylation and signalling show broader expression patterns suggesting movement and signalling of Tre6P outside the vasculature to coordinate plant metabolism and development.