Cloning and Expression Analysis of a Sucrose Phosphate Synthase cDNA Fragment in Melon Fruit

PCR primers were designed based on the conserved domain of some sucrose phosphate synthase genes in GenBank.The target cDNA fragment was amplified from the total RNA isolated from melon fruit of 25 days after pollination with RT-PCR and then was cloned into pMD18-T vector.The sequence showed that the amino acid sequence encoded by this fragment showed a 98.9% similarity to that of the corresponding region of sucrose phosphate synthase gene in tomato.The accession number of this gene in GenBank was DQ355797.Northern blot was performed to analyze the expression pattern of sucrose phosphate synthase in different development stages of melon fruit.The result showed that sucrose phosphate synthase began to express in fruit 25 days after pollination and the expression level of this gene increased with melon fruit mature.