| Popis: |
The rapid escalation in atmospheric carbon dioxide (CO2) is an important cause of global climate change that determines global crop productivity. Under elevated CO2 (EC), there is an initial increase in the rate of photosynthesis (PN) that is frequently accompanied by a decrease of PN and an overall decline in nitrogen (N) and protein concentration. Increasing CO2 concentrations results in a general decrease in the nutritional quality of plant products and thus impacts the food and dietary requirements of the global population. EC often results in a significant increase in the nonstructural carbohydrates and total sugar content while reducing grain proteins and cooking quality. Crops grown under EC also exhibits an average reduction of 8% in 25 minerals, including calcium, potassium, zinc, and iron. Exposure to EC also decreases the ratio of minerals to carbohydrates leading to irreversible impacts on human health, reduction in immunity, malnutrition and stunted growth in children, rise in maternal and child deaths, and also obesity due to the carbohydrate-rich diet. The mechanistic understanding of reduction in crop and grain quality under EC is limited. The dilution of N metabolites and minerals due to higher carbon accumulation, restriction in nutrient uptake due to lower transpiration rate, and reductant availability are the foremost reasons. Recent evidence also suggests the regulatory role of reactive oxygen and nitrogen species in EC-mediated changes in N metabolism and uptake. The current understanding advocates the prominence of identifying CO2 responsive crop genotypes and using genotype-specific fertilizer management for meeting food and nutritional security needs under future EC scenarios. |
