[NO Consumption Ability of Submerged Paddy Soil and the Regulatory Mechanism].

A large number of researches showed that the NO negative emissions from flooding paddy fields, peatlands and other wetlands ecosystem were frequent and considerable, which is of great significance on alleviating the greenhouse gas effect. However, there are few reports about the transformation and microbial mechanism of NO between atmosphere and paddy soil. The slurry of surface paddy soil (0-5 cm) was incubated in laboratory conditions, and the effect of enhanced NO concentrations in headspace on the NO consumption capacity of submerged paddy soil and the response of gene abundance were explored. The results showed that, paddy soil under flooding and anaerobic conditions harbored very strong potential of NO reduction along with a relatively high gene abundance (10 copies·g dry soil at DNA level). Regression analysis presented the NO concentrations in headspace were positively correlated (=1, <0.001) to the NO consumption rates of paddy soil slurry, indicating the high NO concentration could stimulate the NO consumption power, to a very high rate of 4567.99 μg·(m·h). Meanwhile, there were no significant differences in the high abundance of gene among NO treatments, demonstrating the gene abundance at DNA level might not be the main controller of NO consumption ability in submerged paddy soil and further study on the key microbial factor is needed.