Elongation factor thermounstable (EF-Tu) as a key interactor in Candidatus Phytoplasma solani pathogenesis

Candidatus Phytoplasma solani is a bacterium that causes several diseases in agriculturally important crops, particularly in the Mediterranean region [1]. Due to its intracellular parasitic lifestyle, it is an unculturable organism, which hampers the investigation of the mechanisms underlying its pathogenesis. Elongation Factor Thermounstable (EF-Tu) exists in two different variants, associated with the ecological distribution of two different pathogen intermediate hosts, and thus represents a potential mediator of pathogenesis [2]. In this study, recombinant EF- Tu was expressed in Escherichia coli and purified in soluble form. After coupling the protein to magnetic beads, protein extracts from both healthy and infected periwinkles (Catharanthus roseus), chosen as a model organism, were assayed. This approach led to identifying several specific protein interactors for both the health and disease status, fished from the leaf extracts using EF-Tu as bait. Identifying host proteins interacting with EF-Tu will provide insights into Candidatus Phytoplasma solani's pathogenesis molecular mechanisms. This will also contribute to elucidating the interplay between the final and intermediate hosts, posing a way for novel control strategies towards the pest.