Production of hydroxybenzoic acids by Bradyrhizobium japonicum strains after treatment with glyphosate

Glyphosate affects soybean root exudation and rhizosphere micro-organisms

“…Indeed, bacterial growth generally decreased in root exudates of glyphosate-treated plants. Previous research reported that glyphosate concentrations < 1 mM inhibited growth of the symbiotic nitrogen fixing bacterium Bradyrhizobium japonicum [28] due to a combination of sensitivity of B. japonicum to glyphosate and the potential accumulation of cellular glyphosate that could interfere with nodulation and the nitrogen fixation process. Our pseudomonad isolates may also be sensitive to low glyphosate concentrations and therefore interfere with development of populations of beneficial rhizobacteria in the soybean rhizosphere [29].…”

Herbicides Effect on Nitrogen Cycling in Agroecossystems

“…The growth, survival and nitrogenase activity results vary according to the herbicide doses applied, the species/strains studied and the experimental conditions (Faizah et al, 1980;Mallik & Tesfai, 1983;Eberbach & Douglas, 1989;Martensson, 1992;Moorman et al, 1992;Mallik & Tesfai, 1985;Moorman, 1986). Recently, Santos et al (2004) observed differentiated responses in the growth of strains of native Brazilian Bradyrhizobium spp.…”

The Probability of a Horizontal Gene Transfer from Roundup Ready® Soybean to Root Symbiotic Bacteria: A Risk Assessment Study on the GSF Lysimeter Station

“…This might be further increased by the known root exudation of glyphosate (Grossbard and Atkinson 1985). While some laboratory investigations have indicated that glyphosate may inhibit pure cultures of nitrogen-fixing bacteria (Moorman et al 1992;Santos and Flores 1995), effects were only observed at glyphosate concentrations above normal field application rates. Several researchers (Hoagland et al 1999;King et al 2001;Goos et al 2002;Zablotowicz and Reddy 2004) have investigated potential effects of glyphosate herbicides on nitrogen-fixing bacteria associated with glyphosate-tolerant soybeans.…”