THE A-THALIANA DISEASE RESISTANCE GENE RPS2 ENCODES A PROTEIN CONTAINING A NUCLEOTIDE-BINDING SITE AND LEUCINE-RICH REPEATS

In plants, resistance to a pathogen is frequently correlated with a ge netically defined interaction between a plant resistance gene and a co rresponding pathogen avirulence gene. A simple model explains these ge ne-for-gene interactions: avirulence gene products generate signals (l igands), and resistance genes encode cognate receptors. The A. thalian a RPS2 gene confers resistance to the bacterial pathogen P. syringae c arrying the avirulence gene avrRpt2. A map-based positional cloning st rategy was used to identify RPS2. The identification of RPS2 was verif ied using a newly developed transient assay for RPS2 function and by g enetic complementation in transgenic plants. RPS2 encodes a novel 105 kDa protein containing a leucine zipper, a nucleotide-binding site, an d 14 imperfect leucine-rich repeats.