Comparative Transcriptomic and Lipidomic Analysis of Fatty Acid Accumulation in Three Camellia oleifera Varieties During Seed Maturing

Camellia oleifera, a major
woody
oil crop in China, produces tea oil rich in unsaturated fatty acids,
earning it names like liquid gold and eastern olive oil. This study
provides an integrated investigation of the transcriptome and lipidome
within seeds at the maturing process 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. Coordinated high expression of key genes (ACCase, KAS I, KAS II, KAS III, KAR, HAD, EAR, SAD, LPAAT, LACS, DGAT, PDAT) during
the late maturation stage contributes largely to high oil content.
Additionally, expression variations of SAD and FADs among different varieties were explored. The analysis
suggests that high expression of genes such as FAD3, FAD7, and FAD8 notably increased
linolenic acid content. This research provides new insights into the
molecular mechanisms of oil biosynthesis in C. oleifera, offering valuable references for improving yield and quality.

油茶（Camellia oleifera）是中国主要的木本油料作物，其产出的茶油富含不饱和脂肪酸，因此享有“液体黄金”“东方橄榄油”等美誉。本研究对三个油茶品种种子在成熟过程中的转录组（transcriptome）与脂质组（lipidome）开展了整合分析，揭示了脂肪酸生成与脂质合成相关基因之间的显著关联。通过转录组分析，共鉴定出26344个差异表达基因。功能富集分析显示，差异表达基因显著富集于淀粉与蔗糖代谢、植物激素信号转导以及脂质积累等通路。关键基因（ACCase、KAS I、KAS II、KAS III、KAR、HAD、EAR、SAD、LPAAT、LACS、DGAT、PDAT）在成熟后期的协同高表达，是高含油量形成的重要基础。此外，本研究还探究了不同油茶品种间SAD与FADs基因的表达差异。分析结果表明，FAD3、FAD7、FAD8等基因的高表达可显著提升亚麻酸含量。本研究为阐明油茶油脂生物合成的分子机制提供了新视角，同时为提升油茶产量与品质提供了重要参考依据。