Transcriptomic profiling of fatty acid accumulation in Camellia oleifera seed kernels across three developmental stages
This project investigates the molecular regulatory mechanisms underlying oil transformation and fatty acid accumulation in Camellia oleifera (oil-tea camellia) seed kernels during the critical maturation period. Camellia oleifera is an important woody oil crop in China, and the oil transformation stage (August to October) is crucial for determining final oil content and quality.We used the elite cultivar "Ganwu 2" (Camellia oleifera 'Ganwu 2') as experimental material and collected seed kernel samples at three key developmental stages: August, September, and October. Gas chromatography was employed to determine fatty acid composition and content, revealing dynamic changes in oil accumulation. Transcriptome sequencing (RNA-seq) was performed to profile gene expression patterns across these stages.Differential expression analysis identified 1,398 significantly differentially expressed genes (DEGs) primarily enriched in flavonoid biosynthesis, phenylpropanoid biosynthesis, and starch/sucrose metabolism pathways. Weighted gene co-expression network analysis (WGCNA) was conducted to construct gene networks associated with fatty acid traits, identifying a blue module highly correlated with fatty acid characteristics. Within this module, 207 hub genes were identified, including KASIII (beta-ketoacyl-ACP synthase III), a key gene in fatty acid biosynthesis showing significant positive correlation with palmitic acid and palmitoleic acid content. Additionally, 23 PAL (phenylalanine ammonia-lyase) genes, 3 IAA genes, and FLS (flavonol synthase) genes were found to be significantly co-expressed with fatty acid synthesis modules.This study reveals the molecular regulatory network of oil accumulation during Camellia oleifera seed maturation, providing important genetic resources for molecular breeding of high-quality oil-tea camellia varieties.