Cloning and expression analysis of a Chalcone isomerase (CnCHI) gene from chamaemelum nobile

Abstract

Background and Objective: Chamaemelum nobile (C. nobile) is a precious natural medicinal plant, with diverse functions. Chalcone isomerase (CHI gene is one of the key enzyme genes in the synthesis pathway of flavonoids. Information on CHI'gene in C. nobile is relatively lacking. The aim of this study was to characterize a Chalconeisomerase {CnCHI)gene from C.nobile. Methodology: In this study, a CHI gene was cloned from C. nobile, namely, CnCHI (GenBank accession No. MF784449). The expression level of CnCHI gene in different tissues of C nobile was speculated by analyzing the FPKM value from the transcriptome data of C nobile. Results: The sequence analysis and homologous alignment results showed that the CnCHI protein sequence was highly homologous with other CHI protein sequences. CnCHI protein has a Chalcone 3 superfamily conserved domain, highly conserved in evolution, indicating that CnCHI is a member of CHI gene family. CnCHI gene had the closest relationship with Chrysanthemum morffolium CHI gene. The analysis results of FPKM value showed that, the CnCHI expression in the flowers was much higher than in the roots, stems and leaves of C. nobile, indicating that CnCHI gene was a differentially expressed gene. Conclusion: CnCHI was expressed specifically in the flowers of C. nobile. CnCHI is a key enzyme gene in the synthesis pathway of flavonoids in C. nobile.This finding lays the foundation for the production of natural flavonoids.