Expression of a bacterial aroA gene confers tolerance to glyphosate in tobacco plants

Abstract

Glyphosate is a widely used herbicide that inhibits the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS)-encoding aroA gene in the shikimate pathway. The discovery and cloning of the aroA gene with high resistance is central to breeding a transgenic glyphosate-resistant plant. A novel aroA Pantoea gene from Pantoea G-1 was previously isolated and cloned. The aroA Pantoea enzyme was defined as a new class I EPSPS with glyphosate resistance. The aroA Pantoea gene was introduced into tobacco through Agrobacteriummediated transformation. The transgenic tobacco plants were confirmed by PCR, RT-PCR, and Southern blot. The analysis of glyphosate resistance also showed that the transgenic tobacco plants could survive at 15 mM glyphosate; the glyphosate resistance level of the transgenic plants is higher than the agricultural application level recommended by most manufacturers. Overall, this study shows that aroA Pantoea can be used as a candidate gene for the development of genetically modified crops.

Shikimic Acid Pathway in Biosynthesis of Phenolic Compounds

“…Glyphosate (N-(phosphonomethyl)glycine) inhibits EPSPS and is a potent nonselective herbicide that mimics the carbocation of PEP and binds EPEPS competitively [28]. Because the glyphosate is nonselective and kills food crops, there is interest in finding glyphosate-tolerant genes for genetically modified crops [29]. Two types of EPSPS enzymes have been identified: type I EPSPS (sensitive to glyphosate) identified mostly in plants and bacteria and type II EPSPS (nonsensitive to glyphosate and has a high affinity for PEP), found in some bacteria [27].…”

Cloning and Characterization of 5-enopy ruvylshikimate-3-phosphate Synthase from Fragaria vesca

“…carried out to understand glyphosate resistance of EPSPS [8][9][10]. Until now, EPSPS gene has been cloned from from bacteria, fungi, herb plants and wood plants [11][12][13]. Today, there is a great interest in finding glyphosate tolerant genes for GM crops.…”

“…The method of plant vector construction follows the previous report [13]. In order to located in chloroplast, the DNA fragment encoding the chloroplast transit peptide of Arabidopsis (TSP) was connection with the front of the FvEPSPS.…”