Deciphering the molecular regulatory mechanisms of seed oil in soybean for higher-oil breeding

Soybean (Glycine max [L.] Merr.) is one of the most economically valuable crops globally and a predominant source of vegetable oil. Seed oil content, a core trait that shapes soybean seed quality, is governed by complex polygenic regulatory networks. Identifying key regulators and elucidating the molecular mechanisms of seed oil accumulation thus constitute core research priorities in soybean functional genomics. In recent years, advances in genomics and bioinformatics have substantially accelerated soybean functional genomics research, enabling a more comprehensive understanding of the regulatory networks controlling seed oil content. Here, we summarize recent advances in the molecular regulation of seed oil accumulation, including basal lipid metabolic pathways, central transcription factor regulatory modules, phytohormone signaling, and epigenetic regulation. We also discuss breeding strategies for elevating seed oil content and developing high-oil soybean varieties. Overall, this review integrates the latest findings on soybean seed oil biosynthesis and offers theoretical references for subsequent mechanistic investigations and quality improvement.