Synergistic enhancement of soybean yield and quality by diethyl aminoethyl hexanoate: unraveling the molecular mechanisms through integrated transcriptomics

Plant growth regulators like DA-6 can enhance crop productivity and stress tolerance, yet how DA-6 overcomes the common trade-off between yield and seed quality in soybean remains unclear. Using field experiments combined with multi-tissue transcriptomics and weighted gene co-expression network analysis (WGCNA) at key developmental stages, we demonstrate that DA-6 application increases soybean yield by 11.5–13.4% without compromising seed protein or oil content. Mechanistically, DA-6 spatiotemporally reprograms hormone signaling and carbon metabolism, inducing a “seed-like” program in leaves—including de novo expression of storage proteins and oleosins—effectively priming leaves as temporary nutrient reservoirs. During flowering, DA-6 elevates auxin responses and suppresses jasmonate signaling to favor vegetative growth; at pod-filling, it activates jasmonate, cytokinin, and MAPK pathways to enhance stress resilience. Stems are transformed into metabolic hubs through upregulated starch degradation, trehalose metabolism, and cell wall remodeling. WGCNA further linked MAPK signaling to amino sugar metabolism and endocytosis in yield-associated modules. These findings provide a molecular framework for DA-6–mediated synergistic improvement of yield and quality, revealing novel regulatory targets for crop optimization.