Towards sustainable maize production: Glyphosate detoxification by Azospirillum sp. and Pseudomonas sp.

Abstract

To contribute to more sustainable crop production, this study evaluated the capacity of Azospirillum sp. and Pseudomonas sp. to degrade glyphosate residues both in vitro and in vivo in maize plants (Zea mays L.) at different growth stages. In vitro, both bacteria tolerated glyphosate and were capable of using it as a carbon source. In bioassays, inoculation with both bacteria improved germination and root emergence, primary root growth, root hair development and coleoptile growth in seeds previously treated with the herbicide. Foliar inoculation with Azospirillum sp. and Pseudomonas sp. in glyphosate-treated plants improved root and shoot biomass and increased foliar area, photosynthetic pigments and phytohormone content as well, thus increasing maize yield in the field while concomitantly decreasing herbicide accumulation in leaves and grains. The bacterial capacity to degrade glyphosate in vivo at different growth stages in maize plants growing in the field is a novel and promising biotechnological technique to minimize the persistence of xenobiotic compounds in the environment. This finding adds to the already known importance of the application of bacterial inoculants to crops to enhance plant growth, development and yield.