Plant reproduction polynucleotides and methods of use

Abstract

This invention relates to an isolated nucleic acid fragment encoding a reproduction protein. The invention also relates to the construction of a chimeric gene encoding all or a portion of the reproduction protein, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the reproduction protein in a transformed host cell. The invention also provides isolated transcriptional regulatory elements and polynucleotides associated therewith.

1 . An isolated polynucleotide encoding a functional fertilization-independent endosperm (FIE) polypeptide, wherein the full-length sequence of said encoded polypeptide is at least 80% identical to SEQ ID NO: 28, based on BESTFIT, using default parameters.  
     
     
         2 . The isolated polynucleotide of  claim 1 , wherein the full-length sequence of said encoded polypeptide sequence is at least 90% identical to SEQ ID NO: 28, based on BESTFIT, using default parameters.  
     
     
         3 . The isolated polynucleotide of  claim 1 , wherein the nucleotide sequence is at least 80% identical to SEQ ID NO: 27, based on BESTFIT, using default parameters.  
     
     
         4 . The isolated polynucleotide of  claim 1 , wherein the nucleotide sequence is at least 90% identical to SEQ ID NO: 27, based on BESTFIT, using default parameters.  
     
     
         5 . The isolated polynucleotide of  claim 1 , wherein the nucleotide sequence comprises SEQ ID NO: 27.  
     
     
         6 . A recombinant expression cassette, comprising the polynucleotide of  claim 1  or a fragment thereof, which fragment may or may not encode a functional FIE polypeptide, operably linked to a promoter which directs expression in the reproductive tissues of a plant.  
     
     
         7 . The recombinant expression cassette of  claim 6 , wherein said polynucleotide or fragment is operably linked in antisense orientation to said promoter.  
     
     
         8 . A host cell transformed with the recombinant expression cassette of  claim 6 .  
     
     
         9 . A transgenic plant comprising the recombinant expression cassette of  claim 6 .  
     
     
         10 . The transgenic plant of  claim 9 , wherein the plant is  Zea mays.    
     
     
         11 . A method for producing seed in the absence of fertilization, the method comprising reduction of expression, within a plant, of the polynucleotide of  claim 1 .  
     
     
         12 . A method for altering endosperm development in seed, the method comprising modulation of expression, within a plant, of the polynucleotide of  claim 1 .  
     
     
         13 . A method of plant reproduction comprising embryogenesis from callus tissue derived from fie germplasm, wherein tissue-specific downregulation of a CHD polypeptide stimulates embryogenesis and wherein the fie germplasm comprises endosperm development without fertilization.  
     
     
         14 . A method of modulating seed development in a plant, comprising: 
 a) transforming a plant cell with the recombinant expression cassette of  claim 6;     b) growing said plant cell under conditions which favor plant regeneration;    c) regenerating a plant from said transformed plant cell; and    d) growing said plant under conditions which allow or induce expression of said polynucleotide, wherein expression of said polynucleotide results in fertilization-independent endosperm development.