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Lookup NU author(s): Dr Melissa Brazier-Hicks, Dr Sara Franco OrtegaORCiD, Philip Watson, Dr Alina Goldberg Cavalleri, Dr Nawaporn OnkokesungORCiD, Professor Robert Edwards
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2022 The Authors. Published by American Chemical Society.Safeners such as metcamifen and benoxacor are widely used in maize to enhance the selectivity of herbicides through the induction of key detoxifying enzymes, notably cytochrome P450 monooxygenases (CYPs). Using a combination of transcriptomics, proteomics, and functional assays, the safener-inducible CYPs responsible for herbicide metabolism in this globally important crop have been identified. A total of 18 CYPs belonging to clans 71, 72, 74, and 86 were safener-induced, with the respective enzymes expressed in yeast and screened for activity toward thiadiazine (bentazon), sulfonylurea (nicosulfuron), and triketone (mesotrione and tembotrione) chemistries. Herbicide metabolism was largely restricted to family CYP81A members from clan 71, notably CYP81A9, CYP81A16, and CYP81A2. Quantitative transcriptomics and proteomics showed that CYP81A9/CYP81A16 were dominant enzymes in safener-treated field maize, whereas only CYP81A9 was determined in sweet corn. The relationship between CYP81A sequence and activities were investigated by splicing CYP81A2 and CP81A9 together as a series of recombinant chimeras. CYP81A9 showed wide ranging activities toward the three herbicide chemistries, while CYP81A2 uniquely hydroxylated bentazon in multiple positions. The plasticity in substrate specificity of CYP81A9 toward multiple herbicides resided in the second quartile of its N terminal half. Further phylogenetic analysis of CYP81A9 showed that the maize enzyme was related to other CYP81As linked to agrochemical metabolism in cereals and wild grasses, suggesting this clan 71 CYP has a unique function in determining herbicide selectivity in arable crops.
Author(s): Brazier-Hicks M, Franco-Ortega S, Watson P, Rougemont B, Cohn J, Dale R, Hawkes TR, Goldberg-Cavalleri A, Onkokesung N, Edwards R
Publication type: Article
Publication status: Published
Journal: ACS Omega
Year: 2022
Volume: 7
Issue: 20
Pages: 17416-17431
Print publication date: 24/05/2022
Online publication date: 11/05/2022
Acceptance date: 27/04/2022
Date deposited: 11/10/2024
ISSN (electronic): 2470-1343
Publisher: American Chemical Society
URL: https://doi.org/10.1021/ACSOMEGA.2C01705
DOI: 10.1021/ACSOMEGA.2C01705
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