Microbial genetic and enzymatic responses to an anthropogenic phosphorus gradient within a subtropical peatland
Microbial genetic and enzymatic responses to an anthropogenic phosphorus gradient within a subtropical peatland
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DOI：
10.1016/j.geoderma.2016.01.008
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发表时间：
2016-04
期刊：
影响因子：
6.1
通讯作者：
E. Morrison;S. Newman;H. Bae;Zhili He;Jizhong Zhou;K. R. Reddy;A. Ogram
中科院分区：
文献类型：
--
作者：
E. Morrison;S. Newman;H. Bae;Zhili He;Jizhong Zhou;K. R. Reddy;A. Ogram
世界上许多泥炭地都受到农业径流的影响，这可能会通过改变限制养分的浓度来影响基本的地球化学过程。在这项研究中，与磷（P）和氮（N）代谢相关的特定微生物基因的分布与潜在的酶活性相关的P和N的收购在沿着养分梯度在美国佛罗里达大沼泽地的水源保护区2A（WCA-2 A）的土壤中进行了比较。采用定量PCR比较碱性磷酸酶（phoXandphoD）和二氮还原酶（nifH）基因的相对浓度。结合磷酸酶和磷酸二酯酶（EP）的活动进行了比较与亮氨酸氨肽酶的活动（EN），产生一个衡量潜在的微生物投资在P收购相对于N收购。碳酸氢根可提取的有机磷浓度与phoX：nifH（p = 0.049，R2 = 0.77）和phoD：nifH（p = 0.043，R2 = 0.79）基因拷贝数比值之间的显著负相关关系，以及全磷与EP/EN（p = 0.021，R2 = 0.87）之间的显著负相关关系表明，随着碳酸氢根可提取的有机磷和全磷的减少，相对于氮的获取，群落对磷的获取有更大的选择，这表明沿沿着样带从磷限制向氮限制的转变。功能微阵列GeoChip 3.0检测到的独特基因的总数是最大的中间站点，这表明减轻营养限制产生增加的功能多样性。遗传和酶的数据之间的一般协议表明，评估微生物的营养需求与分子技术是可行的，虽然未来的工作需要应用遗传信息作为营养富集的指标。
Many of the world's peatlands are subject to agricultural runoff, which may impact fundamental biogeochemical processes by altering the concentrations of limiting nutrients. In this study, the distribution of specific microbial genes associated with phosphorus (P) and nitrogen (N) metabolism was compared with potential enzyme activities related to P and N acquisition at five stations along a nutrient gradient in soils of Water Conservation Area 2A (WCA-2 A) of the Florida Everglades, USA. Quantitative PCR was used to compare the relative concentrations of genes encoding alkaline phosphatases (phoXandphoD) with those encoding dinitrogenase reductase (nifH). Combined phosphatase and phosphodiesterase (EP) activities were compared with leucine aminopeptidase activities (EN), yielding a measure of potential microbial investment in P acquisition relative to N acquisition. The significant inverse relationship observed between bicarbonate extractable organic P concentrations and ratios of gene copy numbers ofphoX:nifH(p = 0.049, R2= 0.77), andphoD:nifH(p = 0.043, R2= 0.79), combined with the significant inverse relationship between total P and EP/EN(p = 0.021, R2= 0.87), suggest that there is a greater community selection towards P acquisition relative to N acquisition as bicarbonate extractable organic P and total P decrease, suggesting a shift from P limitation to N limitation along the transect. The total number of unique genes detected by the functional microarray GeoChip 3.0 was greatest in an intermediate site, suggesting that the alleviation of nutrient limitation yielded increased functional diversity. The general agreement between genetic and enzymatic data suggests that assessing microbial nutrient demands with molecular techniques is feasible, although future work is needed to apply genetic information as indicators of nutrient enrichment.