Responses of rice qualitative characteristics to elevated carbon dioxide and higher temperature: implications for global nutrition.

Background: Protein and some minerals of rice seed are negatively affected by projected carbon dioxide (CO ) levels. However, an in-depth assessment of rice quality that encompasses both CO and temperature for a wide range of nutritional parameters is not available. Using a free-air CO enrichment facility with temperature control, we conducted a field experiment with two levels of CO (ambient; ambient + 200 ppm) and two levels of temperature (ambient; ambient + 1.5 °C). An in-depth examination of qualitative factors indicated a variable nutritional response.

Results: For total protein, albumin, glutelin, and prolamin, elevated CO reduced seed concentrations irrespective of temperature. Similarly, several amino acids declined further as a function of higher temperature and elevated CO relative to elevated CO alone. Higher temperature increased the lipid percentage of seed; however, elevated CO reduced the overall lipid content. At the nutrient elements level, whereas elevated CO reduced certain elements, a combination of CO and temperature could compensate for CO reductions but was element dependent.

Conclusion: Overall, these data are, at present, the most detailed analysis of rising CO /temperature on the qualitative characteristics of rice. They indicate that climate change is likely to significantly impact the nutritional integrity of rice, with subsequent changes in human health on a global basis. © 2020 Society of Chemical Industry.