Transcriptome and Metabolome Analyses Reveal the Role of FaLEC2 in Regulating Lipid Metabolism in Strawberry.

Abstract

Lipids are vital cellular components with structural, storage, signaling, and defensive functions, and lipid metabolism is critical to strawberry quality. However, the regulatory mechanism underlying lipid metabolism during strawberry development and ripening remains unclear. Although LEAFY COTYLEDON 2 (LEC2) regulates lipid metabolism, its function in strawberries is unknown. This study explored the role of FaLEC2 in strawberries. FaLEC2 is highly expressed during strawberry development. FaLEC2 overexpression delayed ripening, promoted the accumulation of phosphatidylcholines (PCs), including 1,2-dipalmitoyl-3-sn-phosphatidylcholine (DPPC) and PC (16:0/18:3(9Z,12Z,15Z)), and linoleic acid (LA), upregulated FaLOX2.4/2.5/3, downregulated FaLOX5-like2, and regulated various transcription factors (TFs). Correlation analysis revealed associations among lipid metabolites and multiple regulatory genes. Yeast one-hybrid and dual-luciferase reporter assays preliminarily suggested a regulatory association between FaLEC2 and FaPLA1, identifying FaPLA1 as a putative direct target. These findings indicate that FaLEC2 modulates PCs and LA by regulating lipid-related genes, along with a set of candidate TFs, thereby contributing to the regulation of phospholipid and linoleic acid metabolism in strawberries.