In 1987 and 1988, the first field tests of transgenic tobacco resistant to a non selective herbicide, phosphinothricin (PPT) has been realized in France. Compared to the non-transformed tobaccos, the resistant tobaccos reveal identical morphological and agronomical traits. The transfer of the resistance gene to phosphinothricin confers to the tobaccos a high tolerance to this herbicide. The existence of the couple cultivar-herbicide would allow a better efficiency in the control of weeds in tobacco crops.