Glyphosate effect in gene expression, lignine and phosphuros content and yield of soybean with cp4-EPSPS gene

Abstract

Transgenic soybean with the cp4-epsps gene is resistant to the glyphosate application due to the production of an insensitive EPSPs enzyme. It participates in the shikimic acid route and is responsible for producing the following amino acids: phenylalanine, tyrosine and tryptophan. The glyphosate is translocated by the phosphate transporters to the simplast route, reducing the phosphorus content in the cell, leading to the expression of specific phosphorus transporter genes, raising the hypothesis that the glyphosate sub doses application increases these genes expression and also the phosphorus uptake in glyphosate resistant soybean. The shikimic acid route is responsible for the lignin production through the phenylalanine ammonia lyase enzyme. The higher lignin content results in a lower plant growth. Glyphosate sub doses increase plant growth, and the first hypothesis is the reduction of plant lignin contents. The second one is that the greater amount of the EPSPs enzyme results in a higher lignin content and consequently a lower plant growth. So, the glyphosate sub doses application can increase the growth and crop yield, enabling new studies to explain these questions. Thus, the objective of the present work will be to understand the effect process of glyphosate sub doses in soybean plants with the cp4-epsps gene. For this, it will be installed six experiments: five of it in greenhouse and another one in the field. The soybean cultivars used will be the following: The first-generation (RR) and second generation (RR2). The experiments will show the lignin and phosphorus content, as well as the shikimic acid route components throught the chromatography.In addition, the soybean genetic sequencing will also be performed, for understanding which genes are involved in the glyphosate sub doses response, as well as the grain yield. With the results found in the experiments, it is expected to reach the objectives and to achieve the hypotheses. (AU)