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Plant Science Research Horizons seminar with MSc student Quinn Bazinet. Live on Zoom.

Phytopathogens are responsible for substantial crop losses, with up to 16% of total global crop yield being lost to plant pathogens annually. Biotrophic pathogens siphon nutrients from living plant cells while necrotrophic pathogens feed on dead plant tissue. In general, plant resistance to these different pathogenic strategies involves different phytohormone signaling pathways: resistance to biotrophic pathogens is mediated by the salicylic acid pathway while resistance to necrotrophic pathogens is governed by the jasmonic acid and ethylene pathways. How these defensive pathways will be affected by future atmospheric conditions, such as elevated carbon dioxide (CO₂) levels is largely unknown. With current estimates showing an approximate doubling of atmospheric CO₂ by the end of the century, C3 plants will experience changes to metabolic processes, in particular photosynthesis. This may impact plant redox homeostasis and the resultant link to defensive phytohormone activation. To understand how increased atmospheric CO₂ will impact plant resistance, a pathogen bioassay will be used to monitor disease progression in the model C3 plant Arabidopsis thaliana grown in both ambient and elevated CO₂ conditions. As well, quantitative analysis of defensive phytohormones and marker genes associated with the jasmonic acid/ethylene-  and salicylic acid-mediated defense pathways will be conducted. These results will help scientists and agronomists prepare for the major shifts in crop production that will accompany atmospheric CO₂ changes.