Why are soil microbes often a source of herbicide resistance genes?
Soil microbes have been exposed to herbicides for more than 50 years. Such selection pressures typically lead to the evolution of genetically–based resistance mechanisms. It is reasonable to think that the prevalence of herbicide resistance genes in soil microorganisms evolved from such selection. Microbes and plants share many biochemical pathways, so normal physiological functions in microbes will also rely on molecules that are the target sites of herbicides.
