Metabolomic and transcriptomic analysis of the synthesis process of unsaturated fatty acids in Korean pine seed kernels

Due to their rich unsaturated fatty acids, nuts of Korean pine are widely popular in the market. With growing public awareness about forest conservation and healthy eating, the primary focus of Korean pine forest management has gradually shifted from timber to nut production. The lack of understanding of the process of unsaturated fatty acid synthesis in Korean pine kernels and unclear identification of the critical period have hindered efforts to improve yield and genetic modification. This study, through metabolomic and transcriptomic analysis of five developmental stages of Korean pine kernels, identifies the critical period for the synthesis of unsaturated fatty acids, characterizes the gene expression spectrum, and identifies three gene co-expression modules highly correlated with unsaturated fatty acid synthesis. The findings not only provide new insights into the synthesis of oils in gymnosperm nuts but also offer valuable guidance for the cultivation and targeted improvement of high-quality Korean pine nut varieties. • Pine nuts are favored in the market for their unique high content of healthy oils • It is difficult to manage and genetically improve the quality of Korean pine seeds • The synthesis of unsaturated fatty acids (UFAs) in Korean pine nuts is unclear • The synthesis of UFAs occurs in late June, the next year after pollination • Except for KCS , all related genes showed the highest expression levels in late June • Identified 3 co-expressed modules highly related to UFAs synthesis