ABSTRACT
Impact of global climate change and atmospheric pollution have imposed a serious threat to food security in the 21st century and beyond. Elevated [CO2] and [O3] are able to induce physiological and biochemical changes in crops and thus affect their yield and quality. Growth chambers and free-air CO2 enrichment are commonly used to assess agricultural outcomes under the projected future climate. Higher [CO2] mostly caused yield gain of C3 crops due to enhanced photosynthetic activities. However, temperature rise and precipitation variation have been projected to counteract the fertilization effect of CO2. Nevertheless, increased photosynthates accumulation under elevated [CO₂] might also degrade the grain quality. Therefore, suitable agro-technologies are required as adaptive measures. Increasing surface [O3] is another outcome of the changing climate. Anthropogenic activities release precursors (NOx and VOCs) which increased the surface [O₃] by three to five folds in the last 150 years. Uptake of the same through stomata results oxidative stress in plants and significant loss of crop yields. The extent of damage differs among the species depending on the effectiveness of the antioxidants of each crop. Interestingly, elevated [CO₂] can ameliorate the damages caused by O₃ exposure and reduce the risk of yield loss upto 50%.
