Glyphosate has been used globally as a safe herbicide for weed control. It inhibits 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (AroA), which is a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. A Pseudomonas putida strain, 4G-1, was isolated from a soil heavily contaminated by glyphosate in China. Its AroA-encoding gene (aroA) has been cloned, se...

In 2003, a glyphosate-resistant plantago (Plantago lanceolata L.) population located in the Robertson district of South Africa was subjected to different glyphosate dosages and highest dosage (7200 g a.e. ha−1) gave no acceptable levels control. Here we reconfirm resistance investigate mechanism resistance. Dose-response curves indicated that rate causing 50% survival (LD50) for resistant (R) b...

The recombinant gene was amplified from the chromosomal DNA of genetically-modified (GM) soybeans and identified as epsps encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) which renders glyphosate resistance. The epsps structural gene was introduced in the pET28(a) plasmid for its expression in Escherichia coli BL21(DE3). It was confirmed that the maximal productivity of the EPSPS pr...

5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) is a key enzyme in the shikimate pathway and is targeted by the wide-spectrum herbicide glyphosate. Here, we describe the use of a selection system based on directed evolution to select glyphosate-resistant mutants of EPSPS. Using this system, the rice (Oryza sativa) EPSPS gene, mutagenized by Error-Prone polymerase chain reaction, was introdu...

As glyphosate is a broad spectrum herbicide extensively used in agriculture worldwide, identification of new aroA genes with high level of glyphosate tolerance is essential for the development and breeding of transgenic glyphosate-tolerant crops. In this study, an aroA gene was cloned from a Janibacter sp. strain isolated from marine sediment (designated as aroAJ. sp). The purified aroAJ. sp en...

The levels of resistance to glyphosate 13 barnyard grass ( Echinochloa crus-galli ) populations harvested across different agriculture areas in the Southern Iberian Peninsula were determined greenhouse and laboratory experiments. Shikimate accumulation fast screening separated regarding glyphosate: susceptible (S) E2, E3, E4, E6 resistant (R) E1, E5, E7, E8, E9, E10, E11, E12, E13. However, fac...

Chorismate synthase catalyzes the 1,4-elimination of phosphate and the C-(6-pro-R) hydrogen from 5-enolpyruvylshikimate 3-phosphate (EPSP) to generate chorismate. Although this reaction does not involve an overall change in redox state, the enzyme requires reduced FMN. To investigate the role of the flavin in catalysis we have employed chemically modified flavins: 1- and 5-deaza-, 2- and 4-thio...

Transgenic glyphosate-tolerant plants overproducing EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) may exhibit enhanced fitness in glyphosate-free environments. If so, introgression of transgenes overexpressing EPSPS into wild relative species may lead to increased competitiveness of crop-wild hybrids, resulting in unpredicted environmental impact. Assessing fitness effects of transgenes o...

Glyphosate-resistant (GR) Kochia scoparia has evolved in dryland chemical fallow systems throughout North America and the mechanism of resistance involves 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene duplication. Agricultural fields in four states were surveyed for K. scoparia in 2013 and tested for glyphosate-resistance level and EPSPS gene copy number. Glyphosate resistance was co...

A gene has been introduced into soybeans to confer tolerance to glyphosate, the active ingredient in the herbicide, Roundup (Monsanto Co., St. Louis, Mo.) 1,2 Soybean varieties expressing this trait will enable farmers to use Roundup herbicide within the crop during the growing season. Previous studies have confirmed the safety of the introduced protein (5-enolpyruvylshikimate-3-phosphate synth...