anthocyanin-biosynthesis
Anthocyanin biosynthesis is the metabolic pathway by which plants produce anthocyanins, the water-soluble pigments responsible for red, pink, purple, blue, and black coloration in flowers, fruits, and leaves. Understanding this pathway is central to plant science because anthocyanins serve multiple biological roles, including attracting pollinators, protecting tissues from UV radiation, and responding to environmental stresses. Research into the genetic and enzymatic regulation of anthocyanin biosynthesis also has practical applications in improving crop nutritional quality and developing stress-resilient plant varieties.
open_in_new WikipediaPubMed · 2026-02-19
Scientists discovered how a plant defense hormone called salicylic acid triggers the production of red pigments (anthocyanins) in apple fruit, mapping a three-protein chain that acts like a molecular switch. They also found that a second hormone, strigolactone, can dial this process back by breaking up the protein team.
A three-protein module (NPR7 → TGA6 → MYB1) forms the core salicylic acid signaling chain that directly switches on anthocyanin-making genes in apple.
When salicylic acid is absent, an enzyme called RHA2a tags the NPR7 protein for destruction via ubiquitination, effectively shutting the pathway off until defense signals return.
The strigolactone pathway antagonizes anthocyanin production by physically dismantling the NPR7-TGA6 and NPR7-MYB1 protein complexes through the repressor protein SMXL8.
