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 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:3.  
     
     
         2 . An isolated polypeptide comprising 25 contiguous amino acids of SEQ ID NO:3 wherein said polypeptide has metal binding activity.  
     
     
         3 . The polypeptide of  claim 2 , wherein said polypeptide comprises 30 contiguous amino acids.  
     
     
         4 . The polypeptide of  claim 3 , wherein said polypeptide comprises 50 contiguous amino acids.  
     
     
         5 . An isolated polypeptide having 70% sequence identity with SEQ ID NO:3 wherein said polypeptide has metal binding activity.  
     
     
         6 . The polypeptide of  claim 5 , wherein said polypeptide has 80% sequence identity with SEQ ID NO:3.  
     
     
         7 . The polypeptide of  claim 6 , wherein said polypeptide has 90% sequence identity with SEQ ID NO:3.  
     
     
         8 . The polypeptide of  claim 6 , wherein said polypeptide has 95% sequence identity with SEQ ID NO:3.