Soil urease and catalase responses to ozone pollution are affected by the ozone sensitivity of wheat cultivars

Abstract

Understanding the effects of elevated O3 (EO3) on belowground process such as soil enzyme activities is essential to evaluate plant physiological reaction and soil processes (e.g. carbon and nitrogen turnover) under predicted increases in atmospheric O3. In this study, O3-induced changes in soil urease (UA) and catalase activities (CTA) under two contrasting wheat cultivars (O3-sensitive versus O3-tolerant) were investigated using a free-air O3 enrichment (O3FACE) facility in China. EO3 (60 ppb compared with 40 ppb in ambient O3) generally increased UA under the O3-tolerant cultivar but reduced it under the O3-sensitive cultivar for different soil depths and growth stages. In contrast, the e..