Plants comprising wheat g-type cytoplasmic male sterility restorer genes, molecular markers and uses thereof

Abstract

Methods are described for selecting or producing a cereal plant comprising a functional restorer gene for wheat G-type cytoplasmic male sterility and nucleic acids for use therein.

1 . A nucleic acid molecule encoding a functional restorer gene allele for wheat G-type cytoplasmic male sterility, wherein said functional restorer gene allele localizes to the scaffold as represented by SEQ ID NO 15. 
     
     
         2 . The nucleic acid molecule of  claim 1 , wherein said functional restorer gene allele is a functional allele of a PPR gene localising to said scaffold. 
     
     
         3 . The nucleic acid of  claim 1  or  2 , wherein said functional restorer gene allele is a functional allele of a PPR gene encoded by SEQ ID NO. 19, SEQ ID NO. 18 or SEQ ID NO. 16, SEQ ID NO. 21 or of the polypeptide of SEQ ID NO. 20 or SEQ ID NO. 17. 
     
     
         4 . The nucleic acid of any one of  claims 1 - 3 , wherein said functional restorer gene is selected from
 a. A nucleic acid comprising a nucleotide sequence having at least 85% sequence identity to SEQ ID NO. 19, SEQ ID NO 18, SEQ ID NO: 16, SEQ ID NO. 21;   b. A nucleic acid encoding a polypeptide having at least 85% sequence identity to SEQ ID NO.20 or SEQ ID NO. 17.   
     
     
         5 . The nucleic acid of any one of  claims 1 - 4 , wherein said functional restorer gene allele encodes a PPR protein capable of binding to the mRNA of ORF256, preferably to nt 129-146 of SEQ ID NO. 23. 
     
     
         6 . The nucleic acid of any one of  claims 1 - 5 , wherein said functional restorer gene allele is obtainable from USDA accession number PI 583676. 
     
     
         7 . The nucleic acid of any one of  claims 1 - 6 , wherein said functional restorer gene allele comprises the nucleotide sequence of SEQ ID NO. 19, SEQ ID NO 18, SEQ ID NO: 16, SEQ ID NO. 21 or wherein said functional restorer gene allele encodes the polypeptide of SEQ ID NO.20 or SEQ ID NO. 17 
     
     
         8 . A polypeptide encoded by the nucleic acid molecule of any one of  claims 1 - 7 . 
     
     
         9 . A chimeric gene comprising the following operably linked elements
 a. a plant-expressible promoter;   b. a nucleic acid comprising the nucleic acid molecule of any one of  claim 1 - 7  or encoding the polypeptide of  claim 8 ; and optionally   c. a transcription termination and polyadenylation region functional in plant cells,   wherein at least one of said operably linked elements is heterologous with respect to at least one other element.   
     
     
         10 . The chimeric gene of  claim 9 , wherein said promoter is capable of directing expression of the operably linked nucleic acid at least during (early) pollen development and meiosis, such as in anther or, more specifically, tapetum, or developing microspores. 
     
     
         11 . A cereal plant cell or cereal plant or seed thereof, such as a wheat plant cell or plant or seed thereof, comprising the nucleic acid molecule of any one of  claims 1 - 7 , polypeptide of  claim 8 , or the chimeric gene of  claim 9  or  10 , wherein said polypeptide, said nucleic acid, or said chimeric gene in each case is heterologous with respect to said plant cell or plant or seed. 
     
     
         12 . The plant cell, plant or seed of  claim 11 , wherein the polypeptide of  claim 8  is expressed at least during (early) pollen development and meiosis, such as in anther or, more specifically, tapetum, or developing microspore. 
     
     
         13 . The plant cell, plant or seed of  claim 11  or  12 , which is a hybrid plant cell, plant or seed. 
     
     
         14 . A method for producing a cereal plant cell or plant or seed thereof, such as a wheat plant cell or plant or seed thereof, comprising a functional restorer gene for wheat G-type cytoplasmic male sterility, or for increasing restoration capacity for wheat G-type cytoplasmic male sterility (“CMS”) in a cereal plant, such as a wheat plant, comprising the steps of providing said plant cell or plant with the nucleic acid molecule of any one of  claims 1 - 7  or the chimeric gene of  claim 9  or  10 , wherein said providing comprises transformation, crossing, backcrossing, genome editing or mutagenesis. 
     
     
         15 . A method for producing a cereal plant cell or plant or seed thereof, such as a wheat plant cell or plant or seed thereof, comprising a functional restorer gene for wheat G-type cytoplasmic male sterility, or for increasing restoration capacity for wheat G-type cytoplasmic male sterility (“CMS”) in a cereal plant, such as a wheat plant, comprising the steps of increasing the expression of a polypeptide according  claim 8  in said plant cell or plant or seed. 
     
     
         16 . A method for converting a non-restoring cereal plant, such as a wheat plant, into a restoring plant for wheat G-type cytoplasmic male sterility (“CMS”), or for increasing restoration capacity for wheat G-type cytoplasmic male sterility (“CMS”) in a cereal plant, such as a wheat plant, comprising the steps of modifying the genome of said plant to comprise the nucleic acid molecule of any one of  claims 1 - 7  or the chimeric gene of  claim 9  or  10 , wherein said modifying comprises transformation, crossing, backcrossing, genome editing or mutagenesis. 
     
     
         17 . A method for converting a non-restoring cereal plant, such as a wheat plant, into a restoring plant for wheat G-type cytoplasmic male sterility (“CMS”), or for increasing restoration capacity for wheat G-type cytoplasmic male sterility (“CMS”) in a cereal plant, such as a wheat plant, comprising the steps of modifying the genome of said plant to increase the expression of a polypeptide according to  claim 8  in said plant. 
     
     
         18 . A cereal plant cell or cereal plant or seed thereof, such as a wheat plant cell or plant or seed thereof, obtained according to the method of any one of  claims 14 - 17 , preferably wherein said plant has an increased restoration capacity for wheat G-type cytoplasmic male sterility (“CMS”). 
     
     
         19 . The plant cell, plant or seed of  claim 18 , which is a hybrid plant cell, plant or seed. 
     
     
         20 . A method for identifying and/or selecting a cereal (e.g. wheat) plant comprising a functional restorer gene allele for wheat G-type cytoplasmic male sterility comprising the steps of
 a. Identifying or detecting in said plant the presence of a nucleic acid of any one of  claims 1 - 7  or of the polypeptide according to  claim 8 , or the chimeric gene of  claim 9  or  10     b. and optionally selecting said plant comprising said nucleic acid or polypeptide or chimeric gene   
     
     
         21 . The method of  claim 20 , wherein said polypeptide is expressed at least during (early) pollen development and meiosis, such as in anther or, more specifically, tapetum, or developing microspore. 
     
     
         22 . A method for producing a cereal plant, such as a wheat plant, comprising a functional restorer gene allele for wheat G-type cytoplasmic male sterility, comprising the steps of
 a. crossing a first cereal plant, such as a wheat plant, comprising a functional restorer gene for wheat G-type cytoplasmic male sterility of any one of  claim 11 ,  12  or  18  with a second cereal plant   b. identifying a progeny plant comprising a functional restorer gene allele for wheat G-type cytoplasmic male sterility according to the method of  claim 20  or  21 .   
     
     
         23 . A method for producing a cereal plant, such as a wheat plant, comprising a functional restorer gene allele for wheat G-type cytoplasmic male sterility, comprising the steps of
 a. crossing a first cereal plant, such as a wheat plant, homozygous for a functional restorer gene for wheat G-type cytoplasmic male sterility of any one of  claim 11 ,  12  or  18  with a second cereal plant   b. obtaining a progeny plant, wherein said progeny plant comprises said functional restorer gene allele for wheat G-type cytoplasmic male sterility.   
     
     
         24 . A method for producing hybrid seed, comprising the steps of:
 a. Providing a male cereal parent plant, such as a wheat plant, according to  claim 11 ,  12  or  18 , said plant comprising said functional restorer gene allele for wheat G-type cytoplasmic male sterility, wherein said functional restorer gene allele is preferably present in homozygous form.   b. Providing a female cereal parent plant that is a G-type cytoplasmic male sterile cereal plant.   c. Crossing said female cereal parent plant with a said male cereal parent plant; and optionally   d. Harvesting seeds.   
     
     
         25 . Use of the nucleic acid of any one of  claims 1 - 7  to identify one or more further functional restorer gene alleles for wheat G-type cytoplasmic male sterility. 
     
     
         26 . Use of the nucleic acid of any one of  claims 1 - 7  or of the polypeptide according to  claim 8  or of the chimeric gene of  claim 9  or  10  for the identification of a plant comprising said functional restorer gene allele for wheat G-type cytoplasmic male sterility. 
     
     
         27 . Use of a plant according to any one of  claim 11 ,  12  or  18  or a plant obtained by the method of any one of  claim 14 - 17  or  23 - 24 , said plant comprising said functional restorer gene for wheat G-type cytoplasmic male sterility, for restoring fertility in a progeny of a G-type cytoplasmic male sterile cereal plant, such as a wheat plant. 
     
     
         28 . Use of a plant according to any one of  claim 11 ,  12  or  18  or a plant obtained by any one of  claim 14 - 17  or  22 - 23 , said plant comprising said functional restorer gene for wheat G-type cytoplasmic male sterility, for producing hybrid seed or a population of hybrid cereal plants, such as wheat seed or plants.