Ozone induced loss of seed protein accumulation is larger in soybean than in wheat and rice

Abstract

We investigated the effects of ozone (O3) on seed protein accumulation in soybean, rice, and wheat based on existing literature. We identified 30, 10, and 32 datasets meeting the requirements for soybean, rice, and wheat, respectively. Data for each crop were combined in response regressions for seed protein concentration, seed protein yield, and seed yield. Although seed yield in rice was less sensitive to O3 than in wheat, there was a significant positive effect of O3 on the seed protein concentration of the same magnitude in both crops. Soybean, an N-fixing high-protein crop, responded differently. Even though the effect on seed yield was similar to wheat, there was no indication of any effect of O3 on seed protein concentration in soybean. The negative influence of O3 on seed protein yield was statistically significant for soybean and wheat. The effect was larger for soybean (slope of response function: −0.58% per ppb O3) than for wheat (slope: −0.44% per ppb) and especially compared to rice (slope: −0.08% per ppb). The different response of protein concentration in soybean, likely to be associated with adverse O3 effects on N fixation, has large implications for global protein production because of the much higher absolute protein concentration in soybean.