| Plant resistance to broad host range generalist pathogens like Botrytis cinerea is typically quantitative and highly polygenic. A critical aspect to understand plant quantitative resistance is determined by how the interaction is measured. Recent studies have begun to make progress at understanding the molecular genetic basis underpinning plant-pathogen interactions as measured by lesion size and/or pathogen biomass. Yet there are a large number of other interaction measurements that could also describe quantitative resistance that are largely unstudied. In this study, we investigate other previously uncharacterized measures of plant-pathogen interaction such as lesion color and shape using the Arabidopsis/Botrytis pathosystem. Using a large collection of 75 digital measurements of the host-pathogen interaction, we focused on three lesion associated phenotypes that describe lesion color and shape as well as lesion size to test how these aspects of the interaction are or are not genetically related. By conducting genome wide association mapping in Arabidopsis, we were able to show that lesion color and shape are different measurable aspects of the plant-pathogen interaction. Using defined mutants in 23 candidate genes from the genome wide association mapping, we could validate novel causal loci associated with each different trait related to the interaction. |
