Study Of The Evolution And Function Of CYCLOPROPYL STEROL ISOMERASE1Gene Of Plant Sterol Biosynthesis

Plant sterol is significant to the growth and development of plant. It involves in the plants’ response to the drought or adverse stresses. CYCLOPROPYL STEROL ISOMERASE1(CPI1) is a key enzyme of the plant sterol biosynthetic pathway. So far, only the Arabidopsis thaliana CPI1gene has been cloned and studied. In this paper, the Brachypodium distachyon CPI1(BdCPI1) was cloned and functional analysed. In addition, the phenotype of over-expression AtCPI1gene in Arabidopsis thaliana is also discussed. The main results are as follows:1、In this study, we identified single-copy CPI1genes from algae to flowering plants. All CPI1genes from land plants have conserved gene structure and high protein sequence similarity ranging from48-90%, while low protein sequence similarity was observed between land plants and algae. Protein structure prediction found that all CPI1protein have very similar protein structure, with7transmembrane domains and6hydrophilic loops.2、Reverse transcription PCR revealed that the land plants CPI1were constitutive expression genes, indicating that plat CPI1genes may have conserved functions.3、BdCPI1gene was cloned by PCR and its function has been testified by complementation of the Arabidopsis thaliana cpil-1mutant. The results showed that the BdCPIlgene can rescue the cpil-1mutant to wild-type phenotype.4、Two different background (Col-0and Ler) transgenic lines with AtCPI1over-expression are screened. The phenotype of them under normal growing condition and with stress treatments are studied. It is concluded that the background affects the expression of gene and AtCPI1affects the plant growth and their reaction toward stresses.