We have identified an @entity958 mutant that displays enhanced disease resistance to the fungus Erysiphe cichoracearum, causal agent of powdery mildew. The @entity70471 mutant does not constitutively express the pathogenesis-related genes @entity40887 , @entity45042 , or @entity14352 and thus differs from previously described disease-resistant mutants of @entity958 . E. cichoracearum conidia (asexual spores) germinated normally and formed extensive hyphae on @entity70471 plants, indicating that the initial stages of infection were not inhibited. Production of conidiophores on @entity70471 plants, however, was <16% of that observed on wild-type @entity958 . Reduction in sporulation correlated with a more rapid induction of defense responses. Autofluorescent compounds and callose accumulated in @entity70471 leaves 3 days after inoculation with E. cichoracearum, and dead mesophyll cells accumulated in @entity70471 leaves starting 5 days after inoculation. Macroscopic patches of dead cells appeared 6 days after inoculation. This resistance phenotype is similar to that conferred by "late-acting" powdery mildew resistance genes of @entity3505 and @entity2247 . The @entity70471 mutation is recessive and maps to chromosome 1 between molecular markers ATEAT1 and NCC1. We speculate that the @entity70471 mutation derepresses multiple defense responses, making them more easily induced by virulent pathogens.

An XXXX mutant with enhanced resistance to powdery mildew.

@entity2247 :: ('4513', 'Species') :: ['barley'] @entity958 :: ('3702', 'Species') :: ['Arabidopsis'] @entity45042 :: ('824893(Tax:3702)', 'Gene') :: ['BGL2'] @entity14352 :: ('843842(Tax:3702)', 'Gene') :: ['PR-5'] @entity40887 :: ('815949(Tax:3702)', 'Gene') :: ['PR-1'] @entity3505 :: ('4565', 'Species') :: ['wheat'] @entity70471 :: ('837393(Tax:3702)', 'Gene') :: ['edr1']
@entity958 :: (3702,Species) :: ['Arabidopsis']
