The Arabidopsis is Impaired in Resistance to Root and Leaf Necrotrophic Fungal Pathogens.

The () gene is recognised as a marker for early defence and stress responses. To identify regulators of these responses, a forward genetic screen for Arabidopsis mutants with up-regulated promoter activity was conducted by screening a mutagenized population containing a promoter fragment fused to the luciferase reporter gene (). We previously identified several () mutants from this screen that conferred constitutive activity and increased resistance to several pathogens and/or insects pests. Here we identified a further mutant constitutively expressing and termed (). Unlike the mutants, was more susceptible to disease symptom development induced by two necrotrophic fungal pathogens; the root pathogen and the leaf pathogen . The allele was mapped to a 2.1 Mbp region of chromosome 2 and narrowed to four candidate loci.