Cloning and Bioinformatics Analysis of Arabidopsis thaliana DWF4 Gene and Construction of AtDWF4-Overexpression Vector

BRs（Brassinosteroids） is an important steroid hormone in plants, which has very important physiological functions. The DWF 4 is a key rate-limiting enzymein BRs biosynthesis, which significantly affects the content of BRs in plants. In this study, Arabidopsis thaliana was used as the material to clone the objective band. The results showed that a 1 542 bp band from A. thaliana cDNA was cloned and the sequencing results showed that the band was AtDWF4 gene. Bioinformatics analysis showed that this gene encoded 513 amino acid（aa）, and Proscale online predicted that this protein was a hydrophilic protein, and SOPM analysis showed that DWF 4 protein contained multiple secondary structures, including tough-helix, format-fold, and format-angle, etc. Meanwhile, the overexpression vector pRI 201-RdDwf4 containing AtDWF4 gene was also constructed, and the resistant callus and resistant buds were obtained after the genetic transformation of tobacco variety K 326. This paper provides an ideal experimental material for further studying the influence of overexpression of AtDWF4 on tobacco morphology and stress tolerance.