Expression of phosphinothricin acetyltransferase from the root specific par promoter in transgenic tobacco plants is sufficient for herbicide tolerance.

The pat gene, coding for phosphinothricin acetyltransferase (PAT) from Streptomyces viridochromogenes, was cloned behind the par promoter of the hemoglobin gene from Parasponia andersonii, Introduction into tobacco (Nicotiana tabacum) resulted in predominantly root specific PAT expression. Application of 5 l/ha BASTA(®) (herbicidal component: phosphinothricin) did not effect growth morphology and vigor of the plants. After application of 20 l/ha BASTA(®) the plants showed herbicide damage. Nevertheless, they all recovered by forming new undamaged leaves and resumed full growth despite virtually non-detectable expression of the PAT enzyme in the leaves.