Abstract: The protein expressions of longan（Dimocarpus longan Lour.）under low temperature stress were studied using proteomics method. The results showed that the expression of carbonic anhydrase（CA） protein was down-regulated. The CA（GenBank accession number：JN033201）cDNA obtained by RT-PCR was 1 119 bp of full length with a 966 bp open read frame which encodes a putative CA gene with 321 amino acids. Comparison of the amino acids sequences homology in CA from 12 different species indicated that CA had a range of 81% to 88% identity in amino acids sequence with homologues of other plants. The deduced amino acids sequence not only contained a typical CA domain，but also was very conservative. Quantitative real-time PCR results showed that the CA expressed in root，stem and leaf，while the amount of expressions were different in different organs. The mRNA of CA was the most abundant in leaf，the least in root and stem. Furthermore，the mRNA of CA was changed with time extension under low temperature stress. A 40.5 kD heterologous protein was obtained when CA gene was expressed in E. coli. These results suggested that CA might be involved in function of chilling stress.

Key words: longan, chilling stress, proteomics, differential protein, carbonic anhydrase, gene, clone, expression