Epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me) present in leaves of Camellia sinensis has many beneficial biological activities for human health. However, EGCG3"Me occurs naturally in tea leaves in extremely limited quantities. Finding an enzyme from C. sinensis to catalyze the synthesis of EGCG3"Me is an alternative method to make up for the scarcity of EGCG3"Me in natural situations. In the present study, a complementary DNA (cDNA) encoding region and genomic DNA of the caffeoyl-coenzyme A O-methyltransferase (CCoAOMT) gene were isolated from C. sinensis (designated CsCCoAOMT). Nucleotide sequence analysis of CsCCoAOMT revealed an open reading frame of 738 bp that encodes a polypeptide with a predicted molecular weight of 28 kDa, which correlated well with the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The full-length DNA sequence (2678 bp) contained five exons and four introns. The deduced amino acid sequence of CsCCoAOMT shared 92% identity with CCoAOMTs from Codonopsis lanceolata and Betula luminifera. The catalytic activity of CsCCoAOMT was analyzed. Three monomethylated epigallocatechin-3-O-gallate (EGCG) compounds (EGCG4"Me, EGCG3"Me, and EGCG3'Me) were produced by CsCCoAOMT with K(m) in the micromolar range. Real-time polymerase chain reaction (RT-PCR) experiments indicated that the CsCCoAOMT transcript was present at low levels during the early stages of leaf maturity (the first leaf and bud on a shoot) but the relative expression was augmented at advanced stages of leaf maturity (the third or fourth leaf on a shoot), which accorded well with changes in EGCG3"Me content in fresh leaves. Hence, we concluded that CsCCoAOMT catalyzes the syntheses of methylated EGCGs.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4322421 | PMC |
http://dx.doi.org/10.1631/jzus.B1400193 | DOI Listing |
Physiol Plant
December 2024
Laboratory of Tumor Targeted and Immune Therapy, Clinical Research Center for Breast, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China.
As an important source of pollution in the papermaking process, the presence of lignin in poplar can seriously affect the quality and process of pulping. During lignin synthesis, Caffeoyl-CoA-O methyltransferase (CCoAOMT), as a specialized catalytic transferase, can effectively regulate the methylation of caffeoyl-coenzyme A (CCoA) to feruloyl-coenzyme A. Targeting CCoAOMT, this study investigated the substrate recognition mechanism and the possible reaction mechanism, the key residues of lignin binding were mutated and the lignin content was validated by deep convolutional neural-network model based on genome-wide prediction (DCNGP).
View Article and Find Full Text PDFPlants (Basel)
October 2024
Hebei Base of State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Hebei Agricultural University, Baoding 071000, China.
Caffeoyl coenzyme A-O-methyltransferase (CCoAOMT) has a critical function in the lignin biosynthesis pathway. However, its functions in cotton are not clear. In this research, we observed 50 genes from four cotton species, including two diploids (, 9, and ) and two tetraploids (, 16, and ), performed bioinformatic analysis, and focused on the involvement and functions of in lignin synthesis of .
View Article and Find Full Text PDFGene
November 2024
Anhui Provincial Key Laboratory for Quality Evaluation and Improvement of Traditional Chinese Medicine, College of Biological and Pharmaceutical Engineering, West Anhui University, Lu'an 237012, China. Electronic address:
Phytopathology
September 2024
U.S. Department of Agriculture-Agricultural Research Service, Lincoln, NE 68583.
The Fusarium head blight (FHB) pathogen produces the trichothecene mycotoxin deoxynivalenol and reduces wheat yield and grain quality. Spring wheat () genotype CB037 was transformed with constitutive expression (CE) constructs containing sorghum () genes encoding monolignol biosynthetic enzymes caffeoyl coenzyme A (CoA) 3--methyltransferase (), 4-coumarate-CoA ligase (), or coumaroyl shikimate 3-hydroxylase () or monolignol pathway transcriptional activator . Spring wheats were screened for type I (resistance to initial infection, using spray inoculations) and type II (resistance to spread within the spike, using single-floret inoculations) resistances in the field (spray) and greenhouse (spray and single floret).
View Article and Find Full Text PDFTheor Appl Genet
June 2024
Department of Agronomy, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom, Thailand.
The major QTL Sdp1.1+ controlling seed dormancy in cowpea was finely mapped, and two CCoAOMT1 genes were identified as candidate genes for the dormancy. Seed dormancy in wild cowpea may be useful in breeding cultivated cowpea with pre-harvest sprouting resistance.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!