Publications by authors named "Ana Beatriz T B de Figueiredo"
A 2,4-dichlorophenoxyactic acid (2,4-D)-resistant population of (common waterhemp) from Nebraska, USA, was previously found to have rapid metabolic detoxification of the synthetic auxin herbicide 2,4-D. We purified the main 2,4-D metabolites from resistant and susceptible plants, solved their structures by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS), and synthesized the metabolites to determine their toxicity. Susceptible plants conjugated 2,4-D to aspartate to form 2,4-D-aspartic acid (2,4-D-Asp), while resistant plants had a unique metabolic profile where 2,4-D was hydroxylated into 5-OH-2,4-D, followed by conjugation into a sugar metabolite (2,4-D-5--d-glucopyranoside) and subsequent malonylation into 2,4-D-(6'--malonyl)-5--d-glucopyranoside.
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- - The natural plant hormone indole-3-acetic acid (IAA) is crucial for plant growth, while synthetic auxin herbicides like 2,4-D mimic its effects, leading to strong plant responses.
- - A study on a weed population revealed that 2,4-D resistance is linked to a specific 27-nucleotide deletion in the Aux/IAA2 gene, which affects the binding of auxins and cosegregates with herbicide resistance.
- - The findings suggest that this genetic alteration not only explains how weeds develop resistance to synthetic auxins but also offers a potential method for creating genetically modified crops that are resistant to these herbicides through gene editing.