sugar-signaling
Sugar signaling refers to the molecular mechanisms by which plants detect and respond to sugar levels as informational cues, coordinating growth, development, and metabolic processes. Sugars such as sucrose and glucose act not only as energy sources but also as signaling molecules that regulate gene expression, seed germination, root architecture, and responses to environmental stress. Understanding these pathways is critical for improving crop yield, stress tolerance, and the efficiency of carbon allocation throughout the plant.
open_in_new WikipediaPubMed · 2026-04-23
Scientists discovered that a sugar called mannose — released by an enzyme borrowed from four o'clock flowers — triggers a hormone signaling chain in plants that drives root branching and elongation. The mechanism runs through a genetic switch (MYB41) that activates brassinosteroid hormone production, revealing a previously unknown sugar-to-hormone relay governing root architecture.
Mannose released by the MirMAN enzyme significantly promoted both lateral root emergence and root elongation in thale cress, while raising endogenous auxin levels and upregulating at least six auxin-response and lateral-root development genes.
The transcription factor MYB41 was strongly induced by mannose and directly bound the promoter of DWF4 — a brassinosteroid biosynthesis gene — positively regulating its transcription and downstream hormone production.
Mutant plants lacking MYB41 had fewer lateral roots, reduced DWF4 expression, and measurably lower brassinosteroid content, establishing MYB41 as the critical molecular bridge between sugar signaling and hormone-driven root architecture.
