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 the 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.