The contrasting responses of soil microorganisms in two rice cultivars to elevated ground-level ozone

Although elevated ground-level O-3 has a species specific impact on plant growth, the differences in soil biota responses to O-3 pollution among rice cultivars are rarely reported. Using O-3 Free-Air Concentration Enrichment, the responses of the rhizospheric bacterial communities in the O-3-tolerant (YD6) and the O-3-sensitive (IIY084) rice cultivars to O-3 pollution and their differences were assessed by pyrosequencing at rice tillering and anthesis stages. Elevated ground-level O-3 negatively influenced the bacterial community in cultivar YD6 at both rice growth stages by decreasing the bacterial phylogenetic diversities and response ratios. In contrast, in cultivar IIY084, the bacterial community responded positively at the rice tillering stage under O-3 pollution. However, several keystone bacterial guilds were consistently negatively affected by O-3 pollution in two rice cultivars. These findings indicate that continuously O-3 pollution would negatively influence rice agroecosystem and the crop cultivar is important in determining the soil biota responses to elevated O-3. (C) 2014 Elsevier Ltd. All rights reserved.