The present invention relates to the production of a non-transgenic plant
resistant or tolerant to a herbicide of the phosphonomethylglycine
family, e.g., glyphosate. The present invention also relates to the use
of a recombinagenic oligonucleobase to make a desired mutation in the
chromosomal or episomal sequences of a plant in the gene encoding for
5-enol pyruvylshikimate-3-phosphate synthase (EPSPS). The mutated
protein, which substantially maintains the catalytic activity of the
wild-type protein, allows for increased resistance or tolerance of the
plant to a herbicide of the phosphonomethylglycine family, and allows for
the substantially normal growth or development of the plant, its organs,
tissues or cells as compared to the wild-type plant irrespective of the
presence or absence of the herbicide. Additionally the present invention
relates to mutant E. coli cells that contain mutated EPSPS genes.