Abstract: Brassinosteriod is a necessary for plant to regulate the plant physical activities, and DWF1 is one of most critical enzymes involved in brassinosteriod biosynthesis. In order to study the function of DWF1 in melon fruit development, the gene CmDWF1 was cloned from melon for analyzing the nucleotide and amino acid sequences. RT-PCR method was used to analyze the gene expression characteristics. The results showed that the open read frame length of CmDWF1 was 1 701 bp, encoding 566 amino acids. The predicted protein molecular weight of CmDWF1 was 66.115 11 ku, the theoretical isoelectric point was 6.96, the instability index was 48.18 and the GRAVY was -0.402. Signal sequence was not found and the location coefficient in the cytoplasm was 9, which suggested that the protein was localized in cytoplasm. The secondary structure of CmDWF1 protein contained 37.81% of alpha helix, which was relatively high. The CmDWF1 protein contained a FAD-binding-4 domain, which suggested that the protein acted as a FAD oxidoreductase. Phylogenetic analysis showed that Cucumis melo had closer relationship with Cucumis sativus. Real-time fluorescent quantitative analysis indicated that CmDWF1 could express in roots, stems and leaves, but the highest expression level was in roots. And the expression level increased significantly in the 25 d fruit after pollination, but decreased in 35-45 d fruit. These results demonstrated that CmDWF1 might be associated with the biosynthesis of brassinosteriods and then regulated the growth and development of melon.

Key words: Melon, Brassinosteroid, DWF1, Cloning, Expression analysis

CLC Number: 

• S652.03

• Q78