The Effect of High Concentrations of Glufosinate Ammonium on the Yield Components of Transgenic Spring Wheat (Triticum aestivumL.) Constitutively Expressing thebarGene

Abstract

We present an experiment done on a bar + wheat line treated with 14 different concentrations of glufosinate ammonium—an effective component of nonselective herbicides—during seed germination in a closed experimental system. Yield components as number of spikes per plant, number of grains per spike, thousand kernel weight, and yield per plant were thoroughly analysed and statistically evaluated after harvesting. We found that a concentration of glufosinate ammonium 5000 times the lethal dose was not enough to inhibit the germination of transgenic plants expressing the bar gene. Extremely high concentrations of glufosinate ammonium caused a bushy phenotype, significantly lower numbers of grains per spike, and thousand kernel weights. Concerning the productivity, we observed that concentrations of glufosinate ammonium 64 times the lethal dose did not lead to yield depression. Our results draw attention to the possibilities implied in the transgenic approaches.

Pre- and Postnatal Exposure to Low Dose Glufosinate Ammonium Induces Autism-Like Phenotypes in Mice

“…As glyphosate-resistant weeds have begun to develop around the world (Cerdeira and Duke, 2006 ), herbicides containing glufosinate ammonium (GLA, another organophosphorus compound) will probably soon become the best alternative for treating glyphosate-resistant crops, and will therefore be used massively for years. To cope with this, many crop varieties have been genetically engineered to be GLA-tolerant (Ay et al, 2012 ). Accurate assessments of the adverse effects of GLA must therefore be conducted, in particular during the highly sensitive early stages of the life cycle.…”

Biotechnology: Herbicide-Resistant Crops

“…Both genes have been used extensively as selectable markers for selection of transformants (Jones and Sparks, 2009). Use of the bar and pat genes in commercial glufosinate-resistant crops produces a very high level of resistance all the way to flowering and beyond (Áy et al, 2012;Thomas et al, 2004). A concentration of 64 times the lethal dose for nonresistant wheat was reported to have no effect on yield of glufosinate-resistant wheat transformed with the bar gene (Áy et al, 2012).…”

Impairment of motor coordination and interneuron migration in perinatal exposure to glufosinate-ammonium

“…However, the developmental neurotoxic effects of these herbicides are still unclear. Particularly, glufosinate-ammonium (GLA), also known as 2-amino-4-[hydroxy(methyl)phosphoryl] butanoate, is a broad spectrum organophosphorus herbicide used worldwide 9 . GLA is an irreversible inhibitor of the glutamine synthetase required for plants to synthesize glutamine created by introducing ammonia into glutamate 10 .…”

“…Due to the glutamine synthetase expression in astrocytes in the mammalian brain, GLA facilitates neurotoxicity including spatial memory impairments and epileptic activity 11,12 . GLA was developed for genetically modified crops resistant to herbicides and is the first alternative herbicide for glyphosate sprayed on herbicide-resistant crops 9 . As a result, GLA usage is increasing rapidly, but the risks of abnormal cortical development are still unclear.…”