Cloning and Functional Characterization of O-Methyltransferase Gene in Carthamus tinctorius
10.13422/j.cnki.syfjx.20260311
- VernacularTitle:红花O-甲基转移酶基因克隆与功能分析
- Author:
Yongming HUANG
1
;
Yaping LI
1
;
Ping SU
1
;
Meng XIA
1
Author Information
1. State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs， National Resource Center for Chinese Materia Medica， China Academy of Chinese Medical Sciences， Beijing 100700， China
- Publication Type:Journal Article
- Keywords:
Carthamus tinctorius;
O-methyltransferase;
flavonoid;
gene cloning;
functional analysis
- From:
Chinese Journal of Experimental Traditional Medical Formulae
2026;32(9):217-223
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo comprehensively identify the O-methyltransferase （OMT） genes in Carthamus tinctorius and explore the key OMTs that can catalyze the methylation of flavonoids， providing a basis for understanding the molecular formation mechanism of the structural diversity of flavonoids in C. tinctorius. MethodsThe hidden Markov model was used to systematically identify the type Ⅰ OMTs from the high-quality genome data of C. tinctorius. A suite of bioinformatics tools was employed to systematically analyze the physicochemical properties， gene structure， conserved motifs， chromosomal localization， gene replication events， and collinearity of the identified genes. The target gene was heterologously expressed through the prokaryotic expression system of E. coli， and the protein function was verified by in vitro enzymatic reactions. ResultsA total of 31 type Ⅰ OMTs were identified. CtFOMT1 was successfully cloned and expressed in a soluble form in Escherichia coli. The recombinant protein was purified via Ni2+ affinity chromatography to obtain a high-concentration preparation. In vitro enzymatic assays demonstrated that CtFOMT1 utilized S-adenosylmethionine as the methyl donor to catalyze the methylation of the 4′-OH of naringenin， resulting in the production of isosakuranetin. A similar process occurred with the 4′-OH of luteolin， leading to the formation of diosmetin. Subsequent methylation of the 3′-OH group of diosmetin generated 4′-methylchrysoeriol. ConclusionCtFOMT1 can catalyze the methylation of 4′-/3′-OH in the flavonoid skeleton. It is hypothesized that CtFOMT1 may play a role in the biosynthesis of various 4′-/3′-oxymethyl flavonoids in C. tinctorius.
