| Active principle of the herbicide |
Inhibition of |
Target protein |
Herbicide action |
Basis of resistance |
I. Amino acid biosynthesis inhibitors |
| 1. Glyphosate (Roundup)* |
Aromatic amino acid biosynthesis |
EPSPS** |
Broad spectrum |
Overexpression of EPSPS gene; aroA gene from E. coli, Salmonella (insensitive EPSPS) |
| 2. Sulphonylurea and imidazole-nones |
Branched chain amino acids |
Acetolacetate synthase (ALS) |
Selective |
Mutant ALS gene from tobacco, Arabidopois |
| 3. Phosphino-thricin (Basta)* |
Glutamine biosynthesis |
Glutamine synthase |
Broad spectrum |
bar gene from Streptomyces (detoxification) |
| II. Photosynthesis inhibitors |
| 4. Atrazine (Lasso)* |
Photosystem II |
Oβ (32 kDa protein) |
Selective |
Mutant PsbA gene; glutathione-S-transferase gene (detoxification) |
| 5. Bromoxynil (Buctril)* |
Photosynthesis |
-- |
Selective |
bxn gene from Klebsiella (detoxification) |
