油茶是我国重要的木本食用油料树种，茶油（种子油）中油酸含量可接近90%，前期研究发现，油酸的合成分别受SAD和FAD2基因的正负催化作用，但高效积累的分子机制并不清楚。本项目在前期研究基础上，通过油茶CoSAD和CoFAD2基因家族成员的鉴定、亚细胞定位及表达部位检测，种子不同发育阶段CoSAD和CoFAD2基因的表达模式与油酸积累的关联分析等，解析CoSAD和CoFAD2基因对油酸合成的影响机制；通过转基因酵母缺失突变体，同位素标记等，确定CoDGAT1酶对油酸底物选择的特异性；通过CoSAD和CoDGAT1双基因共转化烟草，研究两者协同作用下对油酸积累的影响，并最终揭示油茶油酸高效合成与积累的分子机制。研究结果可为高油酸含量的植物新种质创制提供重要的理论基础和技术支撑。

Oil-tea tree (Camellia oleifera), an important woody edible oil tree species, contains oleic acid of about 90% in its seeds. Previous studies showed that SAD and FAD2 genes played an positive and negative catalyst for biosynthesis and accumulation of oleic acid respectively, but the molecular mechanism is unclear. Based on our previous work, in this project, the regulation mechanism of oleic acid synthesis will be clarified by CoSAD and CoFAD2 cloning, members detection, subcellular localization, expression sites detection, expression patterns, and correlation analysis. The role of CoDGAT1 in oleic acid (18:1) accumulation in TAG will be determined by CoDGAT1 gene cloning, transformation to yeast mutations, and isotope assay. High oleic acid content tobacco lines will be screened by multi-genes co-transformation to tobacco and fatty acid analysis. The regulation mechanism of high accumulation of oleic acid in seeds on molecular level will be finally eluciadated. Our results will be useful for clarification of oleic acid synthesis mechanism in other oil crops, and can provied important theoretical basis for new species breeding with high oleic acid content.