Wang Ling, Xing Xiao-Yi, Qin Hong-Ling, Liu Yi, Wei Wen-Xue
Key Laboratory of Agro-ecological Processes in Subtropical Regions, Taoyuan Station of Agro-Ecology Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Huan Jing Ke Xue. 2017 Apr 8;38(4):1633-1639. doi: 10.13227/j.hjkx.201609138.
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.
大量研究表明，淹水稻田、泥炭地等湿地生态系统中一氧化氮（NO）的负排放频繁且可观，这对缓解温室气体效应具有重要意义。然而，关于大气与稻田土壤之间NO的转化及微生物机制的报道较少。在实验室条件下对表层稻田土壤（0 - 5厘米）的泥浆进行培养，探究顶空NO浓度升高对淹水稻田土壤NO消耗能力及相关基因丰度响应的影响。结果表明，淹水和厌氧条件下的稻田土壤具有很强的NO还原潜力，且相关基因丰度相对较高（DNA水平下为10拷贝·克干土）。回归分析表明，顶空NO浓度与稻田土壤泥浆的NO消耗速率呈正相关（=1，<0.001），表明高浓度NO可刺激NO消耗能力，消耗速率高达4567.99微克·（米·小时）。同时，不同NO处理间相关基因的高丰度无显著差异，表明DNA水平下的相关基因丰度可能不是淹水稻田土壤中NO消耗能力的主要控制因素，需要进一步研究关键微生物因子。
