Bioinformatics Analysis and Functional Verification of Phytoene Synthase Gene PSY1 of C. A. Meyer.

Phytoene synthase (PSY) is a multimeric enzyme that serves as the first enzyme in carotenoid synthesis within plant tissues and plays a crucial role in the production of carotenoids in plants. To understand the function of the PSY gene in C. A. Meyer. fruit, the gene's transcript was obtained by analyzing the transcriptome sequencing data of fruit. The CDS sequence of the gene was cloned from fruit using the RT-PCR cloning technique and named PSY1, which was then subjected to biosynthetic analysis and functional verification. The results showed that the open reading frame of the gene was 1269 bp, encoding 423 amino acids, with a protein molecular mass of 47,654.67 KDa and an isoelectric point (pI) of 8.63; the protein encoded by these amino acids was hydrophilic and localized in chloroplasts, and its three-dimensional structure was predicted by combining the pymol software to annotate the N site of action and active centre of the protein. Phylogenetic analysis demonstrated that PSY1 had the closest affinity to PSY from . Overexpression of PSY1 led to a significant increase in the content of carotenoid-related monomers in , with Violaxanthin being synthesized in transgenic but not in wild-type . The PSY1 clone obtained in this study was able to promote carotenoid synthesis in the fruits of , revealing that the mode of action of PSY1 in the carotenoid biosynthesis pathway of fruits has a positive regulatory effect.