Location: Plant Science ResearchTitle: Potential impacts of ambient ozone on wheat rust diseases and the role of plant ozone sensitivity
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/24/2017
Publication Date: N/A
Technical Abstract: The resurgence of rust diseases and the continued rise in tropospheric ozone (O3) levels have the potential to limit global wheat production. We conducted a series of experiments to understand the potential interactions between these two stress factors. Both stem rust and leaf rust were increased on a rust-susceptible, moderately O3-sensitive winter wheat cultivar exposed to O3 concentrations near current ambient levels (50 ppbv). Enhancement of disease was observed only when plants were pre-exposed for 3 weeks or continuously exposed to 50 ppbv O3. This intermediate treatment did not result in foliar injury, suggesting that changes in leaf chemistry in what appear to be healthy leaves were a contributing factor. No differences in disease were observed between low O3 controls and much higher O3 levels typical of past studies, suggesting the need to re-evaluate the consensus that elevated O3 suppresses wheat rusts. The results suggest that present day air pollution may be impacting wheat production in areas where O3 and rust disease co-occur. This phenomenon was reduced for cultivars with greater rust resistance, suggesting an interaction between O3 sensitivity, rust resistance, and the resulting disease pressure. This interaction is dynamic because cultivar rust resistance may be overcome by pathogen evolution causing the inherent O3 sensitivity to be a critical factor.