Canola event Topas 19/2 was developed from a parent line Topas through Agrobacterium-mediated transformation. Topas 19/2 contains two plant expression cassettes:

• the pat gene expression cassette, which confers tolerance to the broad-spectrum herbicide glufosinate-ammonium. This gene codes for the enzyme phosphinothricin acetyl transferase (PAT), which breaks down phosphinothricin into an inactive form, allowing the modified plants to tolerate application of the herbicide.

• the nptII expression cassette. Expression of this protein confers resistance to the aminoglycoside antibiotics kanamycin, geneticin (G418) and neomycin. It is used for the selection of transformed plants in the laboratory as well as for identification purposes in the field.