Cloning and Sequencing of Expansin cDNA in the Fruits of Chinese Persimmon

With the cDNA in the fruits at the enlarging and maturing stages as the templates and according to the gene sequences of the expansins in other plants,the degenerate primers were constructed to conduct RT-PCR.The product of the amplification were combined with plasimd pUCm-T and then transformed into E.coli JM109.The positive clones were randomly chosen and sequenced,and then two fragments of the expansin cDNA with different sequences were obtained;the fragments were named Cdk-Exp1 and 2.Both the two fragments were located in the conservative regions of expansin gene,i.e.8 cysteine residuals and three tryptophan residuals.Cdk-Exp1 and 2 consisted of 531 bases encoding 177 amino acids and 522 bases encoding 174 amino acids,respectively;the homology of their amino acid sequences reached 92.635% and 92.156% respectively.The expansin cDNA in the fruits of Chinese persimmon was highly homogenous to those in the fruits of strawberry,tomato,and peach on amino acid level.