Methods for making male-sterile plants

Abstract

Compositions and methods for enhancing disease resistance to a pathogen in a plant are provided. Methods of the invention comprise stably transforming a plant with an antisense nucleotide sequence for a gene encoding an enzyme in the C-5 porphyrin metabolic pathway and operably linking said antisense sequence to a pathogen-inducible promoter, such that invasion of a cell by a pathogen elicits a hypersensitive-like response that results in confinement of the pathogen to cells of initial contact. Transformed plants and seeds are provided. Nucleotide sequences encoding a wild-type maize urod gene useful in the present invention and the amino acid sequence for the protein encoded thereby are provided. These compositions are also useful for regulating cell death in specifically targeted tissues. A maize lesion mimic, dominant mutant phenotype, designated Les22, and the molecular basis for its manifestation are also provided.

What is claimed is:  
     
         1 . A method for producing male sterile plants, said method comprising transforming said plant with a DNA construct comprising an antisense nucleotide sequence for a gene encoding an enzyme in the C-5 porphyrin pathway of said plant operably linked to a stamen promoter that drives expression in a plant cell, and regenerating stably transformed plants wherein said gene in the C-5 porphyrin pathway is selected from the group consisting of: 
 (a) the nucleotide sequence set forth in SEQ ID NO: 1;    (b) a nucleotide sequence having 90% sequence identity to the sequence of SEQ ID NO: 1;    (c) a nucleotide sequence having 80% sequence identity to the sequence of SEQ ID NO: 1; and,    (d) a nucleotide sequence that encodes the amino acid sequence set forth in SEQ ID NO: 2.    
     
     
         2 . The method of    claim 1   , wherein said antisense nucleotide sequence comprises at least 20 nucleotides.  
     
     
         3 . A transformed plant having stably integrated into its genome a DNA construct comprising an antisense nucleotide for a gene encoding an enzyme in the C-5 porphyrin pathway of said plant operably linked to a stamen-preferred promoter that drives expression in a plant cell, wherein said gene is selected from the group consisting of: 
 (a) the nucleotide sequence set forth in SEQ ID NO: 1;    (b) a nucleotide sequence having 90% sequence identity to the sequence of SEQ ID NO: 1;    (c) a nucleotide sequence having 80% sequence identity to the sequence of SEQ ID NO: 1; and,    (d) a nucleotide sequence that encodes the amino acid sequence set forth in SEQ ID NO: 2.    
     
     
         4 . The plant of    claim 3   , wherein said antisense nucleotide sequence comprises at least 20 nucleotides.  
     
     
         5 . The plant of    claim 3   , wherein said plant is male-sterile.  
     
     
         6 . The plant of    claim 4   , wherein said plant is male-sterile.  
     
     
         7 . The plant of    claim 3   , wherein said plant is a monocotyledonous plant.  
     
     
         8 . The plant of    claim 7   , wherein said monocotyledonous plant is a maize plant.  
     
     
         9 . The plant of    claim 5   , wherein said plant is a monocotyledonous plant.  
     
     
         10 . The plant of    claim 8   , wherein said monocotyledonous plant is a maize plant.  
     
     
         11 . Transformed seed of the plant of    claim 3   .  
     
     
         12 . Transformed seed of the plant of    claim 5   .  
     
     
         13 . Transformed seed of the plant of    claim 9   .  
     
     
         14 . Transformed seed of the plant of    claim 10   .