Changes in Denitrifier Abundance, Denitrification Gene mRNA Levels, Nitrous Oxide Emissions, and Denitrification in Anoxic Soil Microcosms Amended with Glucose and Plant Residues
Changes in Denitrifier Abundance, Denitrification Gene mRNA Levels, Nitrous Oxide Emissions, and Denitrification in Anoxic Soil Microcosms Amended with Glucose and Plant Residues
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DOI：
10.1128/aem.02993-09
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发表时间：
2010-04-01
影响因子：
4.4
通讯作者：
Goyer, Claudia
中科院分区：
文献类型：
--
作者：
Henderson, Sherri L.;Dandie, Catherine E.;Goyer, Claudia
在农业种植系统中，作物残体是有机碳（C）的来源，是影响反硝化作用的重要因素。红三叶草、大豆和大麦植物残体和葡萄糖对厌氧土壤微宇宙中硝化菌丰度、反硝化基因mRNA水平、一氧化二氮（N2 O）排放和反硝化速率的影响进行了72 h的定量研究。nosZ基因丰度和mRNA水平显着增加响应所有有机碳处理随着时间的推移。与此相反，Mandelii假单胞菌和密切相关的物种（nirS（P））的丰度和mRNA水平仅在葡萄糖改良土壤中增加：nirS（P）公会丰度在72 h的孵育期内增加了5倍（P < 0.001），而mRNA水平在12 h时显著增加了15倍以上（P < 0.001），随后下降。植物残体改良土壤中nosZ基因丰度高于葡萄糖改良土壤。尽管植物残体的碳氮比（C：N）在15：1到30：1之间变化，但nosZ基因和mRNA水平在植物残体处理之间没有显著差异，平均为3.5 x 10（7）个基因拷贝和6.9 x 10（7）个转录本g（-1）干土。累积N2 O排放量和反硝化速率增加超过72小时，在葡萄糖和植物组织碳处理的土壤。nirS（P）和nosZ群落对葡萄糖和植物残基添加剂的反应不同。然而，有针对性的堆肥社区的反应类似于不同的植物残留物的测试条件下，尽管在有机碳的质量和不同的C：N比的变化。
In agricultural cropping systems, crop residues are sources of organic carbon (C), an important factor influencing denitrification. The effects of red clover, soybean, and barley plant residues and of glucose on denitrifier abundance, denitrification gene mRNA levels, nitrous oxide (N2O) emissions, and denitrification rates were quantified in anoxic soil microcosms for 72 h. nosZ gene abundances and mRNA levels significantly increased in response to all organic carbon treatments over time. In contrast, the abundance and mRNA levels of Pseudomonas mandelii and closely related species (nirS(P)) increased only in glucose-amended soil: the nirS(P) guild abundance increased 5-fold over the 72-h incubation period (P < 0.001), while the mRNA level significantly increased more than 15-fold at 12 h (P < 0.001) and then subsequently decreased. The nosZ gene abundance was greater in plant residue-amended soil than in glucose-amended soil. Although plant residue carbon-to-nitrogen (C:N) ratios varied from 15:1 to 30:1, nosZ gene and mRNA levels were not significantly different among plant residue treatments, with an average of 3.5 x 10(7) gene copies and 6.9 x 10(7) transcripts g(-1) dry soil. Cumulative N2O emissions and denitrification rates increased over 72 h in both glucose- and plant-tissue-C-treated soil. The nirS(P) and nosZ communities responded differently to glucose and plant residue amendments. However, the targeted denitrifier communities responded similarly to the different plant residues under the conditions tested despite changes in the quality of organic C and different C: N ratios.