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 (CO2 ) levels. However, an in-depth assessment of rice quality that encompasses both CO2 and temperature for a wide range of nutritional parameters is not available. Using a free-air CO2 enrichment facility with temperature control, we conducted a field experiment with two levels of CO2 (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 CO2 reduced seed concentrations irrespective of temperature. Similarly, several amino acids declined further as a function of higher temperature and elevated CO2 relative to elevated CO2 alone. Higher temperature increased the lipid percentage of seed; however, elevated CO2 reduced the overall lipid content. At the nutrient elements level, whereas elevated CO2 reduced certain elements, a combination of CO2 and temperature could compensate for CO2 reductions but was element dependent. CONCLUSION: Overall, these data are, at present, the most detailed analysis of rising CO2 /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.

Application of FTIR-PAS in Rapid Assessment of Rice Quality under Climate Change Conditions.

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS), versus attenuated total reflectance spectroscopy (FTIR-ATR) and diffuse reflectance spectroscopy (DRIFT), was firstly applied in quick assessment of rice quality in response to rising CO2/temperature instead of conventional time-consuming chemical methods. The influences of elevated CO2 and higher temperature were identified using FTIR-PAS spectra by principal component analysis (PCA). Variations in the rice functional groups are crucial indicators for rice identification, and the ratio of the intensities of two selected spectral bands was used for correlation analysis with starch, protein, and lipid content, and the ratios all showed a positive linear correlation (R 2 = 0.9103, R 2 = 0.9580, and R 2 = 0.9246, respectively). Subsequently, changes in nutritional components under future environmental conditions that encompass higher CO2 and temperature were evaluated, which demonstrated the potential of FTIR-PAS to detect the responses of rice to climate change, providing a valuable technique for agricultural production and food security.