Tackling Multi-Host Pathogenicity of Xylella by Assisted Immunity

ongoing

This project addresses a complex problem in agriculture and will identify the process of multi-host pathogenicity. Emerging and re-emerging disease epidemics represent ongoing challenges to cultivation of crop plants, a global threat to food security and social stability. One of the recent disease epidemics is caused by Xylella fastidiosa, a generalist bacterium that infects a broad range of hosts, now spreading in Europe and threatening olive production. How pathogens colonize in multiple, genetically diverse species across families is poorly understood. X. fastidiosa colonizes xylem vessels, dead cells of the vasculature. I hypothesize that the more complex nature of multi-host pathogen interactions could be explained by a common virulence strategy that depends on environmental circumstances, in terms of resources and immune defences to be overcome. We will use a multi-host approach combined with dual transcriptomics for the systematic analysis of bacterial and plant signatures associated with disease caused by X. fastidiosa. Identifying virulence factors and plant immunity determinants will drive our understanding of host susceptibility. Of translational scientific interest, we will reveal immune receptors that control X. fastidiosa infection. Using this knowledge, we will assist the immune system at different levels of organization of plant tissues by targeted expression of immune receptors. This is high risk/high gain but of strategic relevance for my long-term goal to reduce disease in crops without yield penalties. At its completion, this project will deliver molecular determinants to disease control and an approach to assist immunity in the vasculature, and thus will pave the way for applying similar strategies to other important vascular pathogens. It will also advance our understanding of the more complex nature of multi-host pathogen interactions and our conceptual views of host range determinants.