Natural Prodcut 2-Amino-3-methylhexanoic Acid Stimulates Cucumber Growth via Nutrient and Energy Coordination

Plant growth regulators (PGRs) are vital for modulating plant development and stress responses. This study investigates 2-amino-3-methylhexanoic acid (AMHA), a natural small-molecule bioactive compound, as a potential PGR in cucumber (Cucumis sativus). AMHA, particularly at 100 nM, significantly enhanced root development, trehalose-6-phosphate (T6P) and indole-3-acetic acid (IAA) levels, and uptake of essential nutrients (N, P, K, Fe). It also improved photosynthetic efficiency by upregulating photosynthesis-related genes and enhancing stomatal conductance. Transcriptomic analysis revealed enrichment of differentially expressed genes involved in protein folding, sugar biosynthesis, hormone response, and energy metabolism. AMHA also promoted sucrose synthesis and SWEET-mediated sugar transport, supporting energy-demanding growth processes. Unlike conventional fertilizers, AMHA stimulates endogenous physiological and molecular pathways, representing a sustainable, low-input approach to improving crop productivity. These findings establish AMHA as a promising PGR that coordinates hormone signaling, nutrient uptake, and sugar metabolism to promote vigorous plant growth, offering valuable insights for modern, eco-efficient agriculture.