Whole genome resequencing of the eds4 mutant

The eds4 mutant was identified more than 20 years ago in a screen of ethyl methane sulfonate (EMS)-mutagenized Arabidopsis seedlings for those that were more susceptible to infection with Pseudomonas syringae Psm ES4326. However, attempts to map the position of the underlying mutation failed due to unclear segregation patterns of the disease phenotype when eds4, isolated in the Columbia accession, was outcrossed to other Arabidopsis accessions using traditional positional cloning attempts. By applying a mapping-by-sequencing approach we were able to identify the until now unknown mutation responsible for the eds4 phenotype.