This family consists of several broad-spectrum mildew resistance proteins from Arabidopsis thaliana. Plant disease resistance (R) genes control the recognition of specific pathogens and activate subsequent defence responses. The Arabidopsis thaliana locus Resistance To Powdery Mildew 8 (RPW8) contains two naturally polymorphic, dominant R genes, RPW8.1 and RPW8.2, which individually control resistance to a broad range of powdery mildew pathogens. They induce localised, salicylic acid-dependent defences similar to those induced by R genes that control specific resistance. Apparently, broad-spectrum resistance mediated by RPW8 uses the same mechanisms as specific resistance [1,2].

1: Broad-spectrum mildew resistance in Arabidopsis thaliana mediated by RPW8. Xiao S, Ellwood S, Calis O, Patrick E, Li T, Coleman M, Turner JG; Science 2001;291:118-120. PMID:11141561

2: Enhanced Transcription of the Arabidopsis Disease Resistance Genes RPW8.1 and RPW8.2 via a Salicylic Acid-Dependent Amplification Circuit Is Required for Hypersensitive Cell Death. Xiao S, Brown S, Patrick E, Brearley C, Turner JG; Plant Cell 2003;15:33-45. PMID:12509520