Cloning and sequence analysis of flower color genes in Narcissus tazetta var. chinensis Roem.

[Objective]The present study was aimed to clone and analyze the sequence and structure of PSY,PDS,LycB gene related to flower color in Narcissus tazetta var.chinensis Roem to understand the molecular mechanism of flower color biosynthesis and to provide the basis on further research on carotenoid metabolism genetic engineering in Narcissus tazetta.[Method]The mRNA of Narcissus tazetta flower petals was used as template to amplify three key enzyme genes segment(PSY,PDS and LycB)using Reverse Transcription-Polymerse Chain Reaction(RT-PCR)and its sequence structure was analyzed.[Result]The lengths of conservative sequences in PSY,PDS and LycB were 343,500 and 486 bp,respectively,which encoded 112,166 and 161 amino acids,respectively.Sequence comparison analysis results showed that these genes shared high homology of deduced amino acids with other plants,which ranged from 76.5-96.1,69.8-98.3 and 77.3-95.5%,respectively.Three genes contained the relevant functional domains of PSY,PDS and LycB enzymes in different species,which were proved to be the target genes.The study also indicated that these genes were higher conserved.Further,PSY,PDS and LycB protein had partial lyophobic domains,but no obvious transmembrane protein domains were observed.[Conclusion]These results provide a molecular basis for understanding the regulatory mechanism of flower color enzyme genes and petal pigmentation mechanism in Narcissus tazetta var.chinensis Roem.