Molecular cloning and functional characterization of chalcone isomerase from Carthamus tinctorius

Abstract

Flavonoid is one of the widespread groups of plant secondary metabolites that provide several health benefits. However, the explicit mechanism of flavonoid biosynthesis in plants largely remains unclear. Chalcone isomerase an important class of enzyme presents crucial role during flavonoid metabolism in many plants. Here, we isolated the full-length cDNA (1161 bp) of a novel Chalcone Isomerase from safflower encoding 217 amino acid polypeptide using oligos from 5′ and 3′ ends. The result of Sanger sequencing and phylogenetic analysis revealed that CtCHI is highly homologous to other plants, including typical polyadenylation signals AATAA and Poly A tail. The transient expression in tobacco mesophyll cells using Green Fluorescent Protein tagging determined the subcellular localization of CtCHI in cell membrane and nucleus. The CtCHI ectopic expression in different safflower varieties at different flowering stages showed that CtCHI were found in abundance at the bud stage of Jihong No. 1 . Further correlation analysis between CtCHI expression and flavonoid accumulation at various flowering phases suggested that CtCHI might play a potential role during flavonoid biosynthesis in safflower. In addition, the overexpression of pBASTA-CtCHI in transgenic Arabidopsis infiltrated with floral dip transformation showed relatively higher expression level and increased flavonoid accumulation than wild type. Moreover, the in vitro enzymatic activity and HPLC analysis of transgenic Arabidopsis confirmed the de novo biosynthesis of Rutin. Taken together, our findings laid the foundation of identifying an important gene that might influence flavonoid metabolism in safflower. Electronic supplementary material The online version of this article (10.1186/s13568-019-0854-x) contains supplementary material, which is available to authorized users.

Identification and Characterization of Chalcone Isomerase Genes Involved in Flavonoid Production in Dracaena cambodiana

“…Studies have found that type I CHIs are the bona fide CHIs with enzymatic activity converting naringenin chalcone to naringenin (Ni et al, 2020); overexpression of type I CHI genes increases the content of total flavonoid in various plants (Muir et al, 2001;Li et al, 2006;Park et al, 2011;Chung et al, 2019;Liu et al, 2019;Sun W. et al, 2019;Dare et al, 2020;Ni et al, 2020). In this study, three CHI Type I members were found in D. cambodiana; DcCHI1 may be the key isoform involved in flavonoid biosynthesis.…”

Multi-Omics and miRNA Interaction Joint Analysis Highlight New Insights Into Anthocyanin Biosynthesis in Peanuts (Arachis hypogaea L.)

“…It was suggested that AhCHS could be the first key DEG for early color differentiation in peanut testa, with these results being consistent with previous studies ( Hu et al, 2021a ). It was also found that the expression level of CHI was positively correlated with anthocyanin content ( Liu et al, 2019 ), and that CHI activity could increase the flavonoid content ( Li et al, 2006 ). Additionally, even though AhCHI was consistently highly expressed in Z1, it was first highly expressed in Z2.…”

Anthocyanins in Floral Colors: Biosynthesis and Regulation in Chrysanthemum Flowers

“…CmCHS , CmCHI , and CmF3′H are highly expressed during early developmental stages, whereas, CmF3H , CmDFR , CmANS , and CmUFGT are expressed in a coordinative manner throughout all stages of ray floret development [ 48 ]. The pattern of CmCHI expression was found to be similar among different cultivars with different anthocyanin contents [ 49 , 50 ]. The high expression levels of CmDFR revealed a correlation between anthocyanin accumulation and pink- and white-colored chrysanthemum [ 32 ].…”