Abstract: The cDNA sequence of CaCOI1 was cloned from chili pepper by RT-PCR. Bioinformatics analysis showed that CaCOI1 encodes a putative polypeptide of 603 amino acids with a calculated molecular mass of 68.35 kD and a theoretical pI of 6.32. CaCOI1 protein contains 51.41% α-helical domains，13.76% β-sheet domains，5.80% β-turn，and 29.03% random coil and is hydrophilic with a grand average of hydropathy value of –0.143. CaCOI1 protein was predicted to possess an F-box at the N-terminal and six leucine-rich repeat domains at the C-terminal. Multiple sequence alignments and phylogenetic tree analyses showed that CaCOI1 is close to the tomato LeCOI1 with an overall sequence similarity of 94%. The expression of CaCOI1 was determined by real-time quantitative RT-PCR. The result showed that the CaCOI1 gene was transcribed in different tissue organs. The expression level of CaCOI1 in flowers was about 2.8–5.4 folds higher than that in any other analyzed tissue organs. These results suggest that CaCOI1 may be involved in flower development.

Key words: chili pepper, CaCOI1, cloning, expression