查看文章

Both elevated ozone (O₃) and limiting soil nitrogen (N) availability negatively affect crop performance. However, less is known about how the combination of elevated O₃ and limiting N affect crop growth and metabolism. In this study, we grew tobacco (Nicotiana sylvestris) in ambient and elevated O₃ at two N levels (limiting and sufficient). Results at the whole plant, leaf, and cellular level showed that primary metabolism was reduced by growth in limiting N, and that reduction was exacerbated by exposure to elevated O₃. Limiting N reduced the rates of photosynthetic CO₂ uptake by 40.8% in ambient O₃‐exposed plants, and by 58.6% in elevated O₃‐exposed plants, compared with plants grown with sufficient N. Reductions in photosynthesis compounded to cause large differences in leaf and whole plant parameters including leaf number, leaf area, and leaf and root biomass. These results were consistent with our …