Sugar sensing and signaling in plants. Glucose sensor HXK1 controls multiple biological processes at different glucose concentrations uncoupled from metabolism. Sucrose and glucose metabolism generate diverse sugars and metabolites that could potentially be perceived by distinct sensors. Abbreviations: Acetyl CoA, acetyl coenzyme A; FBP, fructose-1,6-bisphosphatase; G1P, glucose 1-phosphate; G6P, glucose 6-phosphate; Gln, glutamine; GlcNAc, N-acetylglucosamine; HXK, HEXOKINASE; INV, invertase; OGT, O-LINKED N-ACETYLGLUCOSAMINE (O-GLcNAc) TRANSFERASE; R5P, ribose 5-phosphate; RGS1, REGULATOR OF G-PROTEIN SIGNALING1; SNRK1, SNF-RELATED PROTEIN KINASE1; SUS, SUCROSE SYNTHASE; T6P, trehalose 6-phosphate; TOR, TARGET OF RAPAMYCIN; TPP, T6P PHOSPHATASE; TPS, T6P SYNTHASE; UDP, uridine diphosphate.