Concepcion JT, Kaundun SS, Morris JA, Brandenburg AN, Riechers DE. Metabolism of the 4-Hydroxyphenylpyruvate Dioxygenase Inhibitor, Mesotrione, in Multiple-Herbicide-Resistant Palmer amaranth (
Amaranthus palmeri).
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024;
72:5595-5608. [PMID:
38446412 PMCID:
PMC10959109 DOI:
10.1021/acs.jafc.3c06903]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 02/04/2024] [Accepted: 02/08/2024] [Indexed: 03/07/2024]
Abstract
Metabolic resistance to the maize-selective, HPPD-inhibiting herbicide, mesotrione, occurs via Phase I ring hydroxylation in resistant waterhemp and Palmer amaranth; however, mesotrione detoxification pathways post-Phase I are unknown. This research aims to (1) evaluate Palmer amaranth populations for mesotrione resistance via survivorship, foliar injury, and aboveground biomass, (2) determine mesotrione metabolism rates in Palmer amaranth populations during a time course, and (3) identify mesotrione metabolites including and beyond Phase I oxidation. The Palmer amaranth populations, SYNR1 and SYNR2, exhibited higher survival rates (100%), aboveground biomass (c.a. 50%), and lower injury (25-30%) following mesotrione treatment than other populations studied. These two populations also metabolized mesotrione 2-fold faster than sensitive populations, PPI1 and PPI2, and rapidly formed 4-OH-mesotrione. Additionally, SYNR1 and SYNR2 formed 5-OH-mesotrione, which is not produced in high abundance in waterhemp or naturally tolerant maize. Metabolite features derived from 4/5-OH-mesotrione and potential Phase II mesotrione-conjugates were detected and characterized by liquid chromatography-mass spectrometry (LCMS).
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