Roundup (glyphosate) belongs to which major mode-of-action group?

Roundup, which contains the active ingredient glyphosate, belongs to the amino acid synthesis inhibitors group. Glyphosate functions by inhibiting a specific enzyme pathway known as the shikimic acid pathway, which is critical for the synthesis of aromatic amino acids like phenylalanine, tyrosine, and tryptophan in plants and certain microorganisms. This pathway is not present in animals, which is why glyphosate is considered to have a relatively low toxicity to non-target organisms, including humans.

The importance of this mechanism cannot be overstated, as it directly affects the growth and survival of targeted plant species. The inhibition of amino acid synthesis leads to a cascade of metabolic disruptions in plants, ultimately resulting in their death. This mode of action makes glyphosate effective for controlling a wide range of weeds in agricultural and non-agricultural settings.

Other modes of action listed, such as photosynthesis inhibitors or cell division inhibitors, do not pertain to glyphosate's action and therefore, do not describe the correct mechanism by which Roundup operates. Understanding the specific mode of action is essential for effective and responsible pesticide use in managing weeds while considering environmental and safety implications.