Impacts of CO elevation on the physiology and seed quality of soybean.

Understanding the responses of crops to elevated atmospheric carbon dioxide concentrations (E[CO]) is very important in terms of global food supplies. The present study investigates the effects of CO enrichment (to 800 μmol mol) on the physiology of soybean plants and the nutritional value of their seeds under growth chamber conditions. The photosynthesis of soybean was significantly promoted by E[CO] at all growth stages, but leaf area and specific leaf weight were not affected. The levels of mineral elements in the leaves decreased under E[CO]. The soil properties after soybean cultivation under E[CO] were not affected, except for a decrease in available potassium. Moreover, the levels of soluble sugars in the seeds were not affected by E[CO], but the levels of natural antioxidants decreased. In addition, the level of oleic acid decreased under E[CO]. However, levels of fatty acid peroxidation and saturation were maintained. In conclusion, E[CO] appears to have positive effects on the growth of cultivated soybean plants, but its influence on the nutritional values of soybean seeds is complex.