AUTHOR=Uchida Kai , Kim June-Sik , Sato Muneo , Tabeta Hiromitsu , Mochida Keiichi , Hirai Masami Yokota 

TITLE=A metabolome genome-wide association study implicates histidine N-pi-methyltransferase as a key enzyme in N-methylhistidine biosynthesis in Arabidopsis thaliana

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1201129

DOI=10.3389/fpls.2023.1201129

ISSN=1664-462X

ABSTRACT=<p>A genome-wide association study (GWAS), which uses information on single nucleotide polymorphisms (SNPs) from many accessions, has become a powerful approach to gene identification. A metabolome GWAS (mGWAS), which relies on phenotypic information based on metabolite accumulation, can identify genes that contribute to primary and secondary metabolite contents. In this study, we carried out a mGWAS using seed metabolomic data from <italic>Arabidopsis thaliana</italic> accessions obtained by liquid chromatography–mass spectrometry to identify SNPs highly associated with the contents of metabolites such as glucosinolates. These SNPs were present in genes known to be involved in glucosinolate biosynthesis, thus confirming the effectiveness of our analysis. We subsequently focused on SNPs detected in an unknown methyltransferase gene associated with <italic>N</italic>-methylhistidine content. Knockout and overexpression of <italic>A. thaliana</italic> lines of this gene had significantly decreased and increased <italic>N</italic>-methylhistidine contents, respectively. We confirmed that the overexpressing line exclusively accumulated histidine methylated at the pi position, not at the tau position. Our findings suggest that the identified methyltransferase gene encodes a key enzyme for <italic>N</italic>-methylhistidine biosynthesis in <italic>A. thaliana</italic>.</p>