Submitted to: International Workshop on Grapevine Trunk Diseases
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2019
Publication Date: 7/7/2019
Citation: Wallis, C.M., Baumgartner, K., Galarneau, E. 2019. Two infections, one grapevine: How infection by one pathogen may impact that of a second pathogen via induced changes in host physiology. International Workshop on Grapevine Trunk Diseases. p. 58.
Technical Abstract: Grapevine trunk diseases are often characterized by mixed infections resulting from colonization of different pruning wounds by spores of a variety of trunk pathogens. Despite being located on different branches, a first infection may induce systemic changes in host physiology that could alter progress of an independent infection elsewhere on the vine. However, studies examining multiple fungal infections on the same grapevine host are lacking. Therefore, two months after initially infecting grapevines with a trunk pathogen we made a second infection on a different branch, and then monitored the lesion growth of the second infection and compared it to the growth of infections on naïve, not previously-infected plants. Furthermore, we analyzed amino acid, sugar, phenolic compound, and terpenoid levels in stem just prior to the second infection to observe if the initial infections altered levels to disfavor pathogen establishment and growth. Initial inoculation with Botryosphaeria-dieback pathogen Diplodia seriata was associated with reduced lesion lengths of subsequent inoculation with D. seriata, Botryosphaeria-dieback pathogen Neofusiccocum parvum, and Esca pathogen Phaemoniella chlamydospore. Preliminary results suggest these reductions were associated with changes in host physiology including shifts in amino acid, sugar, phenolic compound, and terpenoid levels. Follow-up studies are underway to confirm this phenomenon and examine other pathogen combinations. Results should provide information on how grapevine physiology could be manipulated to better increase disease resistance, and allow fine-tuning of integrated pest management programs based how presence of one pathogen may affect another.