Patent ID: 6737560
Filing Date: 2004-05-18
Classification: A01H,C07K,C12N,C12Y,Y10S

Abstract:
A method to produce hybrid seed with restored male fertility comprising the steps of:(a) inserting into the genome of a plant cell of a pollen producing plant a gene which confers on said plant resistance to an herbicide or antibiotic, and linked to said gene a recombinant DNA molecule comprising: (i) a DNA sequence which codes for a cytotoxic molecule; (ii) a promoter capable of regulating the transcription of said DNA sequence in cells or tissues critical to pollen formation or function; and (iii) a terminator sequence which defines a terminal signal during transcription of such DNA sequence; (b) obtaining a transformed plant cell; (c) regenerating from said plant cell a genetically transformed plant which is male sterile; (d) increasing the number of genetically transformed plants by: (i) crossing the genetically transformed plant described in step (c) above with a suitable male fertile plant; (ii) using an herbicide or antibiotic to eliminate plants which do not contain the genes described in step (a) among plants grown from seed produced by such cross; and (iii) repeating such a cross over several generations with the plants obtained as in step (d)(ii) above in the presence of said herbicide or antibiotic to increase the numbers of male sterile plants; (e) inserting into a plant cell of a suitable male fertile plant selected from the same species a gene which confers on said plant resistance to an herbicide or antibiotic and linked to said gene a recombinant DNA molecule comprising: (i) a DNA sequence which codes for RNA that is complementary to the RNA sequence coding for said cytotoxic molecule; and (ii) a promoter which causes transcription of the DNA sequence defined in step (e)(i) above at or about the time of transcription of the DNA sequence defined in step (a)(i); (f) obtaining a transformed plant cell from step (d); (g) regenerating from said transformed plant cell described in step (d) above a genetically transformed male fertile plant; and (h) producing a restorer line by: (i) selfing the genetically transformed plant described in (g) and selecting from that selfing progeny, a plant homozygous for the male restorer trait; (ii) permitting self-fertilization of said plant homozygous for the male restorer trait; (iii) growing seed of said plant, over a number of generations to increase the number of genetically transformed plants; and (iv) effecting a hybrid cross by pollinating said male sterile plants with pollen from said genetically transformed male fertile plants.