carotenoid-biosynthesis
Carotenoid biosynthesis is the metabolic pathway by which plants produce yellow, orange, and red pigments including carotenes and xanthophylls from isoprenoid precursors. These pigments serve critical functions in plants beyond coloration, acting as accessory light-harvesting molecules in photosynthesis, photoprotective agents that dissipate excess light energy, and precursors to signaling compounds such as abscisic acid and strigolactones. Understanding and manipulating this pathway has broad implications for crop nutritional quality, stress tolerance, and the engineering of plants with enhanced pigment profiles.
open_in_new WikipediaPubMed · 2026-05-02
Scientists have mapped all the molecular switches that control how plants make carotenoids — the pigments behind orange carrots, red tomatoes, and yellow flowers, which also supply vitamin A in our diets. This review synthesizes how hormones, light, stress, and gene-editing tools can tune that master switch to improve crops.
The PSY gene's control region contains multiple responsive elements that react to light, three major plant hormones (abscisic acid, ethylene, and jasmonic acid), and environmental stressors including drought, salinity, and temperature shifts.
Epigenetic mechanisms — DNA methylation, histone modifications, and chromatin remodeling — act as additional layers of regulation that fine-tune carotenoid production without changing the underlying DNA sequence.
CRISPR activation and interference (CRISPRa/i) tools can be targeted directly at the PSY promoter to dial carotenoid production up or down, offering a precise strategy for crop biofortification and stress tolerance engineering.