Novel of Glyphosate-Tolerant Bacterium sp. Strain HA-09 Isolated from Roundup-Contaminated Garden Soils in Iran.

BACKGROUND

Glyphosate is a non-selective systemic herbicide with a broad spectrum of weed control that inhibits a key enzyme, 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, in the shikimate pathway.

OBJECTIVES

Isolation and analysis of the () gene responsible for glyphosate-tolerance in bacteria from Roundup- contaminated soils was the aim of this study.

MATERIALS AND METHODS

Sampling was done from the soil of the gardens which were heavily contaminated by Roundup herbicide and then bacterial screening was performed in the presence of high concentrations of glyphosate. The genus of bacterium was identified via molecular methods such as 16S rRNA sequencing. The gene of this bacterium ( ) was isolated using the primers designed-upon specific regions of genes available in NCBI GenBank database. The PCR product was cloned, sequenced and subcloned into pET28a as an expression vector and transferred into E. coli strain BL21(DE3). The cells were inoculated in liquid M9 minimal medium containing IPTG and different concentrations of glyphosate.

RESULTS

The genus of bacterium was identified as sp. strain HA-09. The isolated gene from this bacterium was approximately 2.2 kb in size. Bioassay of expressing this gene showed high tolerance to glyphosate (up to 300 mM).

CONCLUSION

The gene could be considered as a novel and efficient candidate for development of glyphosate-tolerant crop plants.