Stephen O Duke1, Agnes M Rimando1, Krishna N Reddy2, James V Cizdziel3, Nacer Bellaloui4, David R Shaw5, Martin M Williams6, Jude E Maul7. 1. U.S. Department of Agriculture-Agricultural Research Service, Natural Products Utilization Research Unit, University, MS, USA. 2. USDA-ARS, Crop Production Systems Research Unit, Stoneville, MS, USA. 3. Department of Chemistry and Biochemistry, University of Mississippi, University, MS, USA. 4. USDA-ARS, Crop Genetics Research Unit, Stoneville, MS, USA. 5. Research and Economic Development, Mississippi State University, Mississippi State, MS, USA. 6. USDA-ARS, Global Change and Photosynthesis Research Unit, Urbana, IL, USA. 7. USDA-ARS, Sustainable Agricultural Systems Laboratory, Beltsville, MD, USA.
Abstract
BACKGROUND: There has been controversy as to whether the glyphosate resistance gene and/or glyphosate applied to glyphosate-resistant (GR) soybean affect the content of cationic minerals (especially Mg, Mn and Fe), yield and amino acid content of GR soybean. A two-year field study (2013 and 2014) examined these questions at sites in Mississippi, USA. RESULTS: There were no effects of glyphosate, the GR transgene or field crop history (for a field with both no history of glyphosate use versus one with a long history of glyphosate use) on grain yield. Furthermore, these factors had no consistent effects on measured mineral (Al, As, Ba, Cd, Ca, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Sr, Tl, U, V, Zn) content of leaves or harvested seed. Effects on minerals were small and inconsistent between years, treatments and mineral, and appeared to be random false positives. No notable effects on free or protein amino acids of the seed were measured, although glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), were found in the seed in concentrations consistent with previous studies. CONCLUSIONS: Neither glyphosate nor the GR transgene affect the content of the minerals measured in leaves and seed, harvested seed amino acid composition, or yield of GR soybean. Furthermore, soils with a legacy of GR crops have no effects on these parameters in soybean.
BACKGROUND: There has been controversy as to whether the glyphosate resistance gene and/or glyphosate applied to glyphosate-resistant (GR) soybean affect the content of cationic minerals (especially Mg, Mn and Fe), yield and amino acid content of GR soybean. A two-year field study (2013 and 2014) examined these questions at sites in Mississippi, USA. RESULTS: There were no effects of glyphosate, the GR transgene or field crop history (for a field with both no history of glyphosate use versus one with a long history of glyphosate use) on grain yield. Furthermore, these factors had no consistent effects on measured mineral (Al, As, Ba, Cd, Ca, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Sr, Tl, U, V, Zn) content of leaves or harvested seed. Effects on minerals were small and inconsistent between years, treatments and mineral, and appeared to be random false positives. No notable effects on free or protein amino acids of the seed were measured, although glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), were found in the seed in concentrations consistent with previous studies. CONCLUSIONS: Neither glyphosate nor the GR transgene affect the content of the minerals measured in leaves and seed, harvested seed amino acid composition, or yield of GR soybean. Furthermore, soils with a legacy of GR crops have no effects on these parameters in soybean.
Authors: Ryan M Kepler; Dietrich J Epp Schmidt; Stephanie A Yarwood; Michel A Cavigelli; Krishna N Reddy; Stephen O Duke; Carl A Bradley; Martin M Williams; Jeffery S Buyer; Jude E Maul Journal: Appl Environ Microbiol Date: 2020-02-18 Impact factor: 4.792