Expression genome-wide association analysis (eGWAS) identifies a candidate gene influencing fatty acid composition in soybeans.

The content and composition of fatty acids are crucial determinants of soybean nutritional quality. In this study, we conducted an expression genome-wide association analysis (eGWAS) using 298 soybean germplasm accessions. We identified 904,984 high-quality SNP markers (MAF > 0.02, missing data ≤ 10%). Thirty-three association signals were identified that correlated with to the expression levels of very long chain fatty acid (VLCFA) genes. Integrating KEGG pathway enrichment analysis with gene haplotype analysis, we identified GmLACS11 as the candidate gene that potentially involved in regulating long-chain fatty acid biosynthesis. We performed subcellular localization, bioinformatics analysis, and functional validation of the GmLACS11 gene. The fatty acid content was measured following GmLACS11 gene expression in Saccharomyces cerevisiae eukaryotic expression, Arabidopsis thaliana, and in soybean overexpression and knockout lines. The results demonstrated that both overexpression and knockout of GmLACS11 gene altered soybean fatty acid composition. Overexpression significantly increased the levels of the polyunsaturated fatty acids, linoleic acid and linolenic acid, and a corresponding rise in the total fatty acid content was observed. These findings provide insights into the regulation of soybean very long chain fatty acids biosynthesis and the genetic mechanisms underlying soybean fatty acids composition.