The diversity of the N2O reducers matters for the N2O:N2 denitrification end-product ratio across an annual and a perennial cropping system.
The diversity of the N2O reducers matters for the N2O:N2 denitrification end-product ratio across an annual and a perennial cropping system.
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DOI：
10.3389/fmicb.2015.00971
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发表时间：
2015
影响因子：
5.2
通讯作者：
Philippot L
中科院分区：
文献类型：
--
作者：
Domeignoz-Horta LA;Spor A;Bru D;Breuil MC;Bizouard F;Léonard J;Philippot L
农业是一氧化二氮陆地排放的主要来源，一氧化二氮是一种强效温室气体，也是臭氧层消耗的主要原因。通过携带一氧化二氮还原酶基因（nosZ）的微生物将N2 O还原为N2是已知消除这种温室气体的唯一生物过程。最近的研究表明，一个以前未知的N2 O还原剂分支与土壤作为N2 O汇的能力有关，为减少排放的新战略开辟了道路。在这里，我们调查了农业实践是否可以不同地影响两个N2 O还原剂分支的反硝化最终产品的后果。通过实时PCR定量N2 O-还原剂和生产者的丰度，并通过454焦磷酸测序确定两个nosZ进化枝的多样性。利用潜在N2 O生成量和潜在反硝化活性计算反硝化气体终产物比。总体而言，结果显示管理措施之间的差异有限，但种植制度之间存在显着差异的丰度和结构的nosZII社区，以及在[rN 2 O/r（N2 O +N2）]比。在nosZI群落中观察到更有限的差异，这表明新发现的nosZII分支比nosZI对环境变化更敏感。潜在的反硝化活性和潜在的N2 O生产主要由土壤性质来解释，而nosZII进化枝的多样性本身解释了26%的反硝化最终产物的比例，这突出了了解这一新发现的进化枝的生态学的重要性。
Agriculture is the main source of terrestrial emissions of N2O, a potent greenhouse gas and the main cause of ozone layer depletion. The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only biological process known to eliminate this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers was related to the capacity of the soil to act as an N2O sink, opening the way for new strategies to mitigate emissions. Here, we investigated whether the agricultural practices could differently influence the two N2O reducer clades with consequences for denitrification end-products. The abundance of N2O-reducers and producers was quantified by real-time PCR, and the diversity of both nosZ clades was determined by 454 pyrosequencing. Potential N2O production and potential denitrification activity were used to calculate the denitrification gaseous end-product ratio. Overall, the results showed limited differences between management practices but there were significant differences between cropping systems in both the abundance and structure of the nosZII community, as well as in the [rN2O/r(N2O+N2)] ratio. More limited differences were observed in the nosZI community, suggesting that the newly identified nosZII clade is more sensitive than nosZI to environmental changes. Potential denitrification activity and potential N2O production were explained mainly by the soil properties while the diversity of the nosZII clade on its own explained 26% of the denitrification end-product ratio, which highlights the importance of understanding the ecology of this newly identified clade of N2O reducers for mitigation strategies.