No abstract

Digital imaging allows the identification of genes controlling novel lesion traits. 16Abstract 19 Plant resistance to generalist pathogens with broad host ranges, such as Botrytis cinerea, is 20 typically quantitative and highly polygenic. Recent studies have begun to elucidate the 21 molecular genetic basis underpinning plant-pathogen interactions using commonly measured 22 traits including lesion size and/or pathogen biomass. Yet with the advent of digital imaging and 23 phenomics, there are a large number of additional resistance traits available to study 24 quantitative resistance. In this study, we used high-throughput digital imaging analysis to 25 investigate previously uncharacterized visual traits of plant-pathogen interactions related 26 disease resistance using the Arabidopsis thaliana/Botrytis cinerea pathosystem. Using a large 27 collection of 75 visual traits collected from every lesion, we focused on lesion color, lesion 28 shape, and lesion size, to test how these aspects of the interaction are genetically related. Using 29 genome wide association (GWA) mapping in A. thaliana, we show that lesion color and shape 30 are genetically separable traits associated with plant-disease resistance. Using defined mutants 31 in 23 candidate genes from the GWA mapping, we could identify and show that novel loci 32 associated with each different plant-pathogen interaction trait, which expands our 33 understanding of the functional mechanisms driving plant disease resistance. 34 35 36 99, US NSF grants IOS 1339125, MCB 1330337 and IOS1021861, and the USDA National 595 Institute of Food and Agriculture, Hatch project number CA-D-PLS-7033-H. 596 597 598