Patent ID: 7723576

Claim:
A method of producing male sterile plants, comprising the steps of transforming plant material with a polynucleotide which encodes a first enzyme which is capable of N-acetylating L-phosphinothricin and a second enzyme which is capable of removing the acetyl group from the N-acetyl L-phosphinothricin to yield L-phosphinothricin, and regenerating the thus transformed material into a plant, wherein the first enzyme is expressed in the green tissues of the plant and additionally expressed from a female-specific floral promoter so that the enzyme is present only in green tissues and in reproductive tissues other than those reproductive tissues in which male gametes are rendered non-functional, and wherein L-phosphinothricin herbicide is applied to the plant foliarly up to the time of male gamete formation and/or maturation, so that the plant is substantially undamaged by the application of herbicide, and wherein the second enzyme is expressed preferentially in male reproductive structures so that the selective local regeneration of L-phosphinothricin in these tissues prevents the formation of the said male gametes, or otherwise renders them non-functional.