Effects of Glucose and Its Derivatives on Growth and Nutrient Absorption in Wheat

Glucose and its derivatives serve as key carbon sources and signaling molecules in plants, yet how structurally distinct carbohydrates differentially influence crop growth remains unclear. Our study employed glucose (Glc, -CHO), sorbitol (Sbt, -OH), gluconic acid (GlcA, -COOH), and glucuronic acid (GroA, -COOH; -CHO) as treatment factors, thereby maximizing variation in oxygen-containing functional groups while keeping the C6 carbon backbone constant. A completely randomized hydroponic experiment was established with four concentration levels (0, 10, 25, and 50 mg L−1) to systematically elucidate how glucose and its derivatives influence wheat growth and nutrient uptake, and to clarify the role of functional group chemistry in the performance of carbon-based bio-stimulants. All carbohydrate treatments significantly improved wheat dry matter (17.50–35.00%) and nutrient uptake (N: 17.12–32.18%, P: 21.73–36.97%, K: 12.28–30.51%) compared with the control, primarily by promoting root vigor and nutrient absorption. Among the four carbohydrates, Glc showed the greatest stimulatory effect, significantly enhancing root vigor. Sbt primarily facilitated root elongation and surface area, whereas GlcA and GroA were slightly less effective but still promoted nutrient uptake. The optimal concentrations were 10 mg L−1 for Glc and 25 mg L−1 for its derivatives. These findings provide practical guidance for enhancing nutrient use efficiency and crop productivity using structurally targeted carbohydrates for sustainable agriculture.