GmNFYA11 regulates soybean seed oil content by interacting with and enhancing the transcriptional activity of GmWRI1a

Soybean (Glycine max) ranks among the most crucial oil crops worldwide. Nevertheless, the regulatory mechanisms underlying oil accumulation in soybean are still largely unknown. Here, our study identified GmNFYA11 as an interacting protein of the lipid regulatory factor GmWRI1a and elucidated its role in soybean lipid metabolism. Functional analyses demonstrated that GmNFYA11 was involved in the regulation of fatty acid and oil biosynthesis in soybean. Compared to the wild type, overexpression of GmNFYA11 in transgenic soybean significantly increases oil and total fatty acid content, with altered fatty acid composition. Notably, GmNFYA11 enhances the transcription of GmOLEO1 by specifically binding to the CCAAT-box within its promoter, and physically interacts with GmWRI1a to amplify its transcriptional activity on target genes. Furthermore, we identified five haplotypes of GmNFYA11, with Hap02 associated with higher seed oil content. The higher prevalence of Hap01 and Hap02 in cultivated varieties than in landraces suggests their selection during breeding for high-oil traits. Collectively, GmNFYA11 plays an important role in modulating soybean oil content. This study provides novel insights into the molecular mechanisms underlying fatty acid synthesis. It also clarifies domestication-associated variation in oil content. We propose a regulatory module comprising GmNFYA11 and GmWRI1a, which may serve as a promising target for the genetic improvement of soybean oil production.