Cauliflower mosaic virusdisease spectrum uncovers novel susceptibility factor NCED9 inArabidopsis thaliana

Abstract

AbstractViruses are intimately linked with their hosts and especially dependent on gene-for-gene interactions to establish successful infections. The genotype of their hosts thus has a strong influence on the outcome virus disease. On the host side, defence mechanisms like tolerance and resistance can occur within the same species leading to differing virus accumulation in relation to symptomology and plant fitness. The identification of novel resistance genes and susceptibility factors against viruses is an important part in understanding viral pathogenesis and securing food production. The model plantArabidopsis thalianadisplays a wide symptom spectrum in response to RNA virus infections and unbiased genome-wide association studies have proven a powerful tool to identify novel disease-genes. In this study we infected natural accessions ofArabidopsis thalianawith the pararetrovirusCauliflower mosaic virusto study the phenotypic variations between accessions and their correlation with virus accumulation. Through genome-wide association mapping of viral accumulation differences, we identified several susceptibility factors for CaMV, the strongest of which was the abscisic acid synthesis geneNCED9. Further experiments confirmed the importance of abscisic acid homeostasis and its disruption for CaMV disease.