Isolation and characterization of gain-of-function cell death mutant in Arabidopsis

Abstract

Hypersensitive response (HR), which is a dominant plant response associated with resistance to pathogen attack, leads to rapid local cell death to restrict growth and spread of the pathogen. To clarify mechanisms involved in HR-induced cell death, FOX hunting system was used to isolate gain-of-function mutants. The isolated mutant, which shows brown- or black-colored lesions on leaves, is caused by over-expression of the gene encoding transcription factor that contains an ERF/AP2 domain. Microarray analysis using the mutant revealed that the genes involved in pathogenic resistance such as beta-glucanase, chitinase, defensine and H₂O₂-inducible GST are extremely up-regulated. These results suggest that the cell death phenotype in the mutant is due to activation of HR and biotic stress response. The detailed characterization of the mutant will be reported.