Comparative transcriptomic and lipidomic analysis of fatty acid accumulation in three Camellia oleifera varieties during maturation

Camellia oleifera stands out as one of Chinas leading woody oil crops, famed for its tea oil, which boasts a high content of unsaturated fatty acids. Often referred to as "liquid gold" or "Oriental olive oil," this oil is prized for its nutritional benefits and culinary versatility, marking Camellia oleifera as a valuable agricultural and economic resource. This study provides an integrated investigation of the transcriptome and lipidome within seeds at the maturation stage across three C. oleifera varieties, revealing a significant relationship between fatty acid production and genes involved in lipid synthesis. Through transcriptomic analysis, 26,344 genes with varied expression were found. Functional enrichment analysis highlighted that pathways related to starch and sucrose metabolism, plant hormone signal transduction, and lipid accumulation were highly enriched among the differentially expressed genes. Additionally, expression variations of SAD and FADs among different varieties were explored. The analysis suggests that increased expression of genes such as FAD3, FAD7, and FAD8 during the maturation stage may enhance the proportion of linolenic acid while reducing oleic acid content. This alteration could potentially stimulate fatty acid synthesis through a feedback regulation mechanism, thereby enhancing seed oil content. These findings provide a novel perspective on the feedback regulation mechanisms underlying lipid biosynthesis in C. oleifera seeds, offering significant insights to boost oil yield and improve tea oil quality.