Project description:To better understand plant-pathogen interactions and the activation of defense mechanisms, this study proposes to identify the differentially abundant proteins in an interspecific hybrid of passion fruit and its parents, Passiflora edulis and P. setacea, inoculated with CABMV compared to their non-inoculated counterparts. Leaves from the three populations were inoculated and collected 72 h after inoculation. The experiment was set up as a completely randomized design with three replicates. Of the over 500 identified proteins, 100, 290, and 96 were differentially abundant for the hybrid, P. edulis, and P. setacea, respectively, in response to CABMV. In the interspecific hybrid, 41% of the proteins were down-regulated and 59% were up-regulated, compared to control. In the P. setacea parent, 39% of the protein being down-regulated. The P. edulis parent, in turn, showed a distinct profile, in which 82% of the protein were down-regulated and only 18% were up-regulated compared to control. It is suggested that CABMV suppresses accumulation of proteins in susceptible species that may have a key function in plant defense response, such as those linked to proteasome regulation and heat shock proteins. At the same time, it should regulate the accumulation of proteins that may impair viral signaling within the host such as glutathione peroxidase. Despite responding to the infection, P. edulis was not capable of stopping the disease establishment. Results suggest that the disease manifests due to a failure in the signaling system of susceptible species, whose activated response pathways are not sufficient to control it.