Glyphosate and Aminomethylphosphonic Acid Content in Glyphosate-Resistant Soybean Leaves, Stems, and Roots and Associated Phytotoxicity Following a Single Glyphosate-Based Herbicide Application

• Published in: Journal of agricultural and food chemistry 2019-06, Vol.67 (22), p.6133-6142
• Main Authors: Smedbol, Élise, Lucotte, Marc, Maccario, Sophie, Gomes, Marcelo Pedrosa, Paquet, Serge, Moingt, Matthieu, Mercier, Lila Lucero Celis, Sobarzo, Millaray Rayen Perez, Blouin, Marc-André
• Format: Article
• Language: English
• Subjects: Glycine - analogs & derivatives; Glycine - analysis; Glycine - metabolism; Glycine - pharmacology; Glycine max - chemistry; Glycine max - drug effects; Glycine max - metabolism; Glyphosate; Herbicide Resistance; Herbicides - analysis; Herbicides - metabolism; Herbicides - pharmacology; Organophosphorus Compounds - analysis; Organophosphorus Compounds - metabolism; Plant Leaves - chemistry; Plant Leaves - drug effects; Plant Leaves - metabolism; Plant Roots - chemistry; Plant Roots - drug effects; Plant Roots - metabolism; Plant Stems - chemistry; Plant Stems - drug effects; Plant Stems - metabolism
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.9b00949

Glyphosate-based herbicide (GBH) applications were reported to induce physiological damages to glyphosate-resistant (GR) soybean, which were mainly attributed to aminomethylphosphonic acid (AMPA). In order to study glyphosate and AMPA dynamics in plants and associated phytotoxic effects, a greenhouse experiment was set where GR soybeans were exposed to GBH (0.7 to 4.5 kg glyphosate ha–1) and sampled over time (2, 7, 14, and 28 days after treatment (DAT)). Hydrogen peroxide content increased 2 DAT, while a decrease was observed for the effective quantum yield (2, 7, 14 DAT), stomatal conductance (2 DAT), and biomass (14 DAT). Glyphosate content was higher in leaves, followed by stems, and then roots. AMPA content tended to increase with time, especially in roots, and the amount of AMPA in roots was negatively correlated to mostly all phytotoxicity indicators. This finding is important since AMPA residues are measured in agricultural soils several months after GBH applications, which could impact productivity in GR crops.