Maize metallothionein gene and promoter

Abstract

The present invention provides compositions and methods for regulating expression of heterologous nucleotide sequences in a plant. Compositions include a novel nucleotide sequence for a root-preferred promoter for the gene encoding, a metallothionein gene and sequences isolated therefrom. A method for expressing a heterologous nucleotide sequence in a plant using the promoter sequences disclosed herein is provided. The method comprises transforming a plant cell with a nucleotide sequence operably linked to one of the root-preferred promoters of the present invention and regenerating a stably transformed plant that expresses the nucleotide sequence in a root-preferred manner from the transformed plant cell. Compositions and methods for expressing metallothionein genes in plants, plant cells and tissues are also provided. The compositions comprise nucleotide sequences encoding plant metallothionein. The sequences are useful in transforming plants for tissue-preferred or constitutive expression of metallothionein. Such sequences find use in modulating levels of metal ions in plants and plant tissues.

What is claimed is:  
     
         1 . An isolated nucleic acid that is capable of driving transcription in a plant, wherein said nucleic acid comprises a nucleotide sequence having 95% sequence identity to the nucleotide sequence set forth in SEQ ID NO:1.  
     
     
         2 . A DNA construct comprising the nucleic acid of  claim 1  and a nucleotide sequence operably linked to said nucleic acid.  
     
     
         3 . A vector comprising the DNA construct of  claim 2 .  
     
     
         4 . A plant stably transformed with a DNA construct comprising a first nucleic acid capable of driving transcription in a plant cell and a second nucleotide sequence operably linked to said first nucleic acid, wherein said nucleic acid comprises a nucleotide sequence having 95% sequence identity to the nucleotide sequence set forth in SEQ ID NO:1.  
     
     
         5 . The plant of  claim 4 , wherein said plant is a monocot.  
     
     
         6 . The plant of  claim 5 , wherein said monocot is maize.  
     
     
         7 . The plant of  claim 4 , wherein said plant is a dicot.  
     
     
         8 . Transformed seed of the plant of  claim 4 , wherein said seed comprises said expression cassette in its genome.  
     
     
         9 . A method for expressing a nucleotide sequence in a plant, said method comprising transforming a plant cell with a transformation vector comprising a DNA construct, and regenerating a stably transformed plant from said plant cell, said DNA construct comprising a first nucleic acid capable of driving transcription in a plant cell and a second nucleotide sequence operably linked to said nucleic acid, wherein said nucleic acid comprises a nucleotide sequence having 95% sequence identity to the nucleotide sequence set forth in SEQ ID NO:1.  
     
     
         10 . The method of  claim 9 , wherein expression of said operably linked second nucleotide sequence alters the phenotype of said plant.  
     
     
         11 . A plant cell stably transformed with a DNA construct comprising a first nucleic acid capable of driving transcription in a plant cell and a second nucleotide sequence operably linked to said first nucleic acid, wherein said nucleic acid comprises a nucleotide sequence having 95% sequence identity to the nucleotide sequence set forth in SEQ ID NO:1.  
     
     
         12 . A promoter element selected from the group consisting of: 
 a) a promoter element having the nucleotide sequence TATGAGATGA;    b) a promoter element having the nucleotide sequence CGAT CGACAA;    c) a promoter element having the nucleotide sequence GGCACAAGA;    d) a promoter element having the nucleotide sequence GATATAGA T;    e) a promoter element having the nucleotide sequence set forth in SEQ ID NO:9;    f) a promoter element having the nucleotide sequence AGAGCACGC;    g) a promoter element having the nucleotide sequence AGT TCTG;    h) a promoter element having the nucleotide sequence AGCTGTA; and    i) a promoter element having the nucleotide sequence AT AGATTAC.    
     
     
         13 . A promoter having at least one copy of at least one promoter element of  claim 12 .  
     
     
         14 . A method for constructing a promoter capable of driving root-preferred expression in a plant cell, said method comprising operably linking a nucleotide sequence comprising a core promoter to at least one copy of at least one promoter element of  claim 12 .  
     
     
         15 . A method for selectively expressing a nucleotide sequence in a plant root, said method comprising transforming a plant cell with a transformation vector comprising an expression cassette, and regenerating a stably transformed plant from said plant cell, said expression cassette comprising a promoter and a nucleotide sequence operably linked to said promoter, wherein said promoter is capable of initiating root-preferred transcription of said nucleotide sequence in a plant cell, and wherein said promoter comprises at least one copy of at least one promoter element of  claim 12 .  
     
     
         16 . A plant cell stably transformed with an expression cassette comprising a promoter and a nucleotide sequence operably linked to said promoter, wherein said promoter is capable of initiating root-preferred transcription of said nucleotide sequence in a plant cell, wherein said promoter comprises at least one copy of at least one promoter element of  claim 12 .  
     
     
         17 . A plant stably transformed with an expression cassette comprising a promoter and a nucleotide sequence operably linked to said promoter, wherein said promoter is capable of initiating root-preferred transcription of said nucleotide sequence in a plant cell, wherein said promoter comprises at least one copy of at least one promoter element of  claim 12.