Plant growth regulators (PGRs) play a critical role in modulating plant development and stress responses. This study investigates the mechanism by which 2-amino-3-methylhexanoic acid (AMHA), a novel natural small-molecule PGR, stimulates cucumber growth. Results show that AMHA increased trehalose-6-phosphate and indole-3-acetic acid levels, promoting root development. The improved root architecture enhanced the uptake and utilization efficiency of key nutrients, including N, P, K, and Fe. In shoots, AMHA upregulated photosynthetic genes (CHL27, MgCh, LHCB3, LHCB4, and PsbY), leading to an increased stomatal conductance and net photosynthetic rate. Additionally, elevated sucrose production in source leaves, coupled with its SWEET-transporter-mediated allocation to sink tissues, further fueled growth. By integrating these pathways, AMHA targets core physiological and molecular processes, demonstrating strong potential to improve crop productivity. These findings establish AMHA as a promising PGR that coordinates phytohormone signaling, nutrient uptake, and sucrose metabolism to enhance plant vigor, offering valuable insights for modern, eco-friendly agricultural practices.
Yang et al. (2026) studied this question.