Abstract

Carbohydrate partitioning is crucial for sprout growth and nutritional quality, yet its co-regulation by environmental and metabolic cues remains unclear. Here, we showed that myo-inositol modulates sugar allocation in a light-specific manner in Chinese kale sprouts. Red light promoted glucose and fructose accumulation and induced the expression of starch biosynthetic genes, and blue light reduced sucrose and pigment levels. Myo-inositol enhanced sugar accumulation under all light conditions; monosaccharides increased under red light, and sucrose increased under blue light. Integrated transcriptomic and metabolomic analyses revealed that myo-inositol and red light synergistically promote starch metabolism, jasmonic acid signaling, and phenylpropanoid and glucosinolate biosynthesis. Under blue light, carbon flow was redirected toward antioxidant defense. Co-expression network analysis identified GRFs and WRKYs as key regulators associated with sugar metabolism and glucosinolate biosynthesis. These findings uncover a light-dependent mechanism in which myo-inositol coordinates carbohydrate and metabolic reprogramming and have implications for improving sprout quality. © 2025 The Authors