Genetic reduction of male fertility in plants

Abstract

A nuclear maize gene is mutated to result in dominant male sterility. Two mutants are provided which impact signal peptide processing. Restoration constructs and methods are provided for use of the dominant male-sterile mutants in producing hybrid seed for male-sterile hybrid plants. Other signal-peptide modifications are provided. Orthologs of the wild type or mutated gene in various species are provided.

1 - 113 . (canceled) 
     
     
         114 . A method for creating hybrid seed heterozygous for a nuclear gene or construct conferring dominant male sterility, the method comprising
 a. growing male-sterile inbred plants, wherein the male-sterile phenotype is conferred by a nuclear gene or first construct wherein said nuclear gene or first construct comprises a Ms44 mutant polynucleotide sequence encoding a polypeptide comprising a non-functional secretory signal peptide, wherein expression of the polypeptide comprising the non-functional secretory signal peptide in the plant confers a dominant male-sterile phenotype to the plant;   b. pollinating said male-sterile inbred plants with a second inbred which is male-fertile, and further comprises a second construct comprising an element that suppresses the expression of the Ms44 mutant polynucleotide encoding the polypeptide comprising the non-functional secretory signal peptide or the expression of the polypeptide comprising the non-functional secretory signal peptide; and   c. harvesting hybrid seed from said male-sterile inbred plants, wherein said seed is heterozygous for a nuclear gene or construct conferring dominant male sterility.   
     
     
         115 . The method of  claim 114 , further comprising planting said harvested seed to produce hybrid plants which are heterozygous for the gene or construct conferring dominant male sterility. 
     
     
         116 . The method of  claim 114 , wherein the male-sterile inbred plants are homozygous for the nuclear gene or first construct conferring dominant male sterility. 
     
     
         117 . The method of  claim 114 , wherein the second inbred is homozygous for said nuclear gene or first construct conferring dominant male sterility. 
     
     
         118 . The method of  claim 114 , wherein the element that suppresses the expression of the Ms44 mutant polynucleotide is selected from the group consisting of antisense, RNAi, and hairpin molecules directed to the nuclear gene or construct conferring male sterility. 
     
     
         119 . The method of  claim 118 , wherein the suppression element is a promoter inverted repeat targeting the promoter driving the nuclear gene conferring male sterility. 
     
     
         120 . The method of  claim 114 , wherein the element that disrupts pollen function encodes a gene product which interferes with the normal accumulation of starch in pollen or affects osmotic balance within pollen. 
     
     
         121 . The method of  claim 114 , wherein the second construct comprises a marker expressed in seed tissue. 
     
     
         122 . The method of  claim 114 , wherein said Ms44 mutant polynucleotide sequence conferring dominant male sterility is selected from the group consisting of: a nucleic acid of SEQ ID NO: 13, 15, and 152. 
     
     
         123 . The method of  claim 114 , wherein the nuclear gene or Ms44 mutant polynucleotide sequence encodes SEQ ID NO: 14 or 153. 
     
     
         124 . The method of  claim 114 , wherein the nuclear gene or Ms44 mutant polynucleotide sequence is a maize nuclear gene or Ms44 mutant polynucleotide sequence. 
     
     
         125 . The method of  claim 121 , further comprising sorting said harvested seed based on the seed tissue marker.