Gene involved in pyrimidine biosynthesis in plants

Abstract

This invention relates to an isolated nucleic acid fragment encoding an OMP decarboxylase. The invention also relates to the construction of a chimeric gene encoding all or a portion of the OMP decarboxylase, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the OMP decarboxylase in a transformed host cell.

What is claimed is:  
     
         1 . An isolated polynucleotide that encodes a polypeptide of at least 200 amino acids having a sequence identity of at least 85% based on the Clustal method of alignment when compared to a polypeptide selected from the group consisting of SEQ ID NOs:6, 8, 10, and 12.  
     
     
         2 . A polynucleotide sequence of  claim 1 , wherein sequence identity is at least 90%.  
     
     
         3 . A polynucleotide sequence of  claim 1 , wherein sequence identity is at least 95%.  
     
     
         4 . The polynucleotide of  claim 1  wherein the polynucleotide encodes a polypeptide selected from the group consisting of SEQ ID NOs:6, 8, 10 and 12.  
     
     
         5 . The polynucleotide of  claim 1 , wherein the polynucleotide comprises a nucleotide sequence selected from the group consisting of SEQ ID NO:5, 7, 9 and 11.  
     
     
         6 . The polynucleotide of  claim 1 , wherein the polypeptide is an OMP decarboxylase.  
     
     
         7 . An isolated complement of the polynucleotide of  claim 1 , wherein (a) the complement and the polynucleotide consist of the same number of nucleotides, and (b) the nucleotide sequences of the complement and the polynucleotide have 100% complementarity.  
     
     
         8 . An isolated nucleic acid molecule that (1) comprises at least 800 nucleotides and (2) remains hybridized with the isolated polynucleotide of claim  24  under a washing condition of 0.1×SSC, 0.1% SDS, and 65° C.  
     
     
         9 . A cell comprising the polynucleotide of  claim 1 .  
     
     
         10 . The cell of  claim 9 , wherein the cell is selected from the group consisting of a yeast cell, a bacterial cell and a plant cell.  
     
     
         11 . A transgenic plant comprising the polynucleotide of  claim 1 .  
     
     
         12 . A method for transforming a cell comprising introducing into a cell the polynucleotide of  claim 1 .  
     
     
         13 . A method for producing a transgenic plant comprising (a) transforming a plant cell with the polynucleotide of  claim 1 , and (b) regenerating a plant from the transformed plant cell.  
     
     
         14 . A method for producing a polynucleotide fragment comprising (a) selecting a nucleotide sequence comprised by the polynucleotide of  claim 1 , and (b) synthesizing a polynucleotide fragment containing the nucleotide sequence.  
     
     
         15 . The method of  claim 14 , wherein the fragment is produced in vivo.  
     
     
         16 . An isolated polypeptide comprising (a) at least 200 amino acids, and (b) a first amino acid sequence, wherein the first amino acid sequence and a second amino acid sequence have a sequence identity of at least 85%, and wherein the second amino acid is selected from the group consisting of SEQ ID NOs:6, 8, 10, and 12.  
     
     
         17 . The polypeptide of  claim 16 , wherein the sequence identity is at least 90%.  
     
     
         18 . The polypeptide of  claim 16 , wherein the sequence identity is at least 95%.  
     
     
         19 . The polypeptide of  claim 16  wherein the polypeptide has a sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, and 12.  
     
     
         20 . The polypeptide of  claim 16 , wherein the polypeptide is an OMP decarboxylase.  
     
     
         21 . A chimeric gene comprising the polynucleotide of  claim 1  operably linked to at least one suitable regulatory sequence.  
     
     
         22 . A method for altering the level of OMP decarboxylase.expression in a host cell, the method comprising: 
 (a) Transforming a host cell with the chimeric gene of  claim 21;  and    (b) Growing the transformed cell in step (a) under condistions suitable for the expression of the chimeric gene.