A Preliminary Study On The Role Of Arabidovsis CER9 Gene In Regulating Seed Oil Synthesis

Vegetable oil is not only the main source of fatty acids, especially the unsaturated fats for humans, but also is an important industrial raw material. With the increasing population and the improving living standard, China’s edible oil demand is increasing. On the contrary, the domestic edible oil supply is showing a serious shortage, which is significantly influencing our national food security. Therefore, studying mechanisms oil synthesis and improving oil contents of oil crops with biotechnique, which has important theory significance and high application value. In recent years, great progress has been made in the cloning of plant lipid synthesis related genes and understanding of their transcriptional regulation metabolism, however, the regulation of lipid synthesis at post-translational level remain unkown.The CER9 gene which encodes a putative E3 ubiquitin ligase, has been shown to be involved in the regulation of epicuticular wax and cutin sythesis. Our latest results found its role in regulating seed oil synthesis. The seed oil content of CER9 gene deletion mutant cer9-2 has a 17% increase when compared to wild type Col-0. Further, we screened the CER9 interacting proteins with yeast hybrid system, finding a LPAT2 which encodes a endoplasmic reticulum lysophospholipid acyltransferase can directly interact with CER9. LPAT2 plays an important role in the synthesis process of seed oil, therefore we speculate that CER9 may affect the oil synthesis through interaction with LPAT2. We also constructed and identified LPAT2 overexpression transgenic plants and the Salk 04681T-DNA insertion mutant-respectively, laying the foundation for further analysis of genetic relationship between CER9 and LPAT2. In addition, this study also use the prokaryotic recombinant system to express and purify the necessary proteins for CER9 ubiquitination analysis, including El, E2, E3 (CER9-RING) and ubiquitin like protein. With the purified proteins ubiquitin antibody was prepared and demonstrated. All the above materials should powerful help for further biochemical experiments.