Cloning and Characterization of Undaria pinnatifida Suringar Phytoene Desaturase Gene Enhancing Carotenoid Accumulation in Transgenic Tobacco

The phytoene desaturase is a key enzyme involved in the carotenoid biosynthesis pathway, which catalyzes the conversion of I¶-carotene from phytoene. In this study, he PDS gene (UpPDS) was isolated and characterized from Undaria pinnatifida Suringar, the full-length cDNA sequence was 1707 bp in length and encoded 568 amino acid residues. Then, the plant expression vector pCAMBIA2300-UpPDS was constructed and transformed into Agrobacterium LBA4404, and then transferred into tobacco plants by infection. Transgenic tobacco plants were identified by PCR amplification and southern blotting. Assay of real-time quantitative PCR ananlysis indicated that the expression level of the target gene UpPDS differed greatly in different transgenic tobacco plants. Spectrophotometry was used to determine the carotenoids content in the leaves trangenic plants, and the results showed that the content of carotenoids in the leaves of transgenic plants was higher than that of wild tobacco, and the maximum content increased 1.13 times compared with that of wild plants.