Detoxification OR Degradatoin of Herbicides -
A number of detoxifying enzymes have been identified in plants as well as in microbes. For example, glutathione-S-transferase enzyme found in maize and other plants detoxifies the herbicide atrazine, while nitrilase (encoded by gene bxn from Klebsiella pneumoniae) detoxifies the herbicide bromoxynil.

Similarly, phosphinothricin acetyltransferase encoded by bar gene from Streptomyces spp. detoxifies the herbicide L-phosphinothricin.

Transgenic tomato, potato, oilseed rape (Brassica napus) and sugarbeet plants expressing the bar gene from Streptomyces have been obtained; these were found to be resistant to the herbicide phosphinothricin.

Similarly, transgenic tomato plants expressing the bxn gene from Klebsiella were resistant to the herbicide bromoxynil. Field trails with transgenic herbicide resistant crops have been very successful, and several such varieties are in commercial cultivation, especially in U.S.A.