Synthesis, Plant Growth Regulatory Activity, and Transcriptome Analysis of Novel Opabactin Analogs.

Abscisic acid (ABA), a phytohormone, and its analogs have been found to enhance plant resistance to various biotic and abiotic stresses, particularly drought, by activating the ABA signaling pathway. This study used a combination of structure-directed design and molecular docking screening methods to synthesize a novel series of opabactin (OP) analogs. Among them, compounds - and showed comparable or superior activity to OP in bioassays, including seed germination and seedling growth inhibition in and rice, stomatal closure, and drought resistance in wheat and soybean. Further transcriptome analysis revealed distinct mechanisms of action between compound and -PhABA in enhancing drought tolerance in . These findings highlight the application prospect of and its analogs in agricultural cultivation, particularly in drought resistance. Additionally, they provide new insights into the mechanisms by which different ABA receptor agonists enhance drought resistance.