Phospholipid 13C stable isotopic probing during decomposition of wheat residues
Phospholipid 13C stable isotopic probing during decomposition of wheat residues
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DOI：
10.1016/j.apsoil.2015.09.009
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发表时间：
2016-02-01
影响因子：
4.8
通讯作者：
Boeckx, Pascal
中科院分区：
文献类型：
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作者：
Bai, Zhen;Liang, Chao;Boeckx, Pascal
解析土壤微生物群落演替的动力学，可以丰富我们对秸秆还田条件下微生物碳（C）利用模式的认识。这种理解可能是有用的，以预测特定的微生物功能群的快速反应，并制定战略，平衡陆地碳预算。因此，我们的目标是表征和估计参数的微生物群落动力学概况磷脂脂肪酸（PLFA）从C-13标记的小麦残留物和SOM。我们进行了为期21天的微观世界研究，使用两种不同的耕地系统（传统耕作，CT;免耕，NT）修改与三种类型的C-13标记的小麦残留物（谷物，叶子和根）。利用气相色谱-燃烧-同位素比值质谱（GC-c-IRMS）和气体示踪同位素比值质谱（IRMS）分别测定了（CO2）-C13通量和C13标记PLFA的丰度和同位素组成。采用双指数模型描述了不同微生物来源的PLFA的合成-降解动力学。我们发现，PLFA的形成一般在7天内达到其最大丰度（放线菌的PLFA除外）。的总和和小麦残留衍生的碳通量，以及他们的PLFA配置文件，不一致的影响残留物质量或耕作制度在孵化期。具体而言，残留来源的CO2和PLFAs的丰度显着降低以下顺序：籽粒>叶>根。然而，这些丰度来自SUM是最低的叶渣处理。残留衍生PLFA模式的真菌和G细菌的影响很大，而G细菌和放线菌PLFA优先链接到现存的SUM矿化。与残留物衍生的对应物相比，SUM衍生的微生物的特征在于更高的G（+）/G细菌和cy 17：01 C16：1 omega 7 c比率，以及更低的真菌/细菌PLFA比率。秸秆和SUM之间的这种区别也证明了对比耕作对C矿化的影响和CY 17：01 C16：1 Ω 7 C和真菌/G细菌PLFA的比例。我们的研究提供了证据，通过残留物质量控制适应微生物介导的土壤碳管理过程的重要影响。(C)2015 Elsevier B. V.版权所有。
Disentangling the kinetics of the soil microbial community succession, which is simultaneously driven by newly added plant materials and extant soil organic matter (SUM), can enrich our knowledge on microbial carbon (C) utilization patterns under residue amendment. This understanding might be useful to predict the rapid responses of specific microbial functional groups and develop strategies for balancing the terrestrial C budget. Therefore, our objective was to characterize and estimate the parameters of the microbial community dynamics profiled by phospholipid fatty acids (PLFA) from C-13-labeled wheat residues and SOM. We conducted a 21-day microcosm study using two different arable systems (conventional tillage, CT; no-till, NT) amended with three types of C-13-labeled wheat residues (grains, leaves and roots). The abundances and isotopic fractions of (CO2)-C-13 flux and C-13-labeled PLFA were measured via gas trace isotope ratio mass spectrometry (IRMS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-c-IRMS), respectively. A double exponential model was used to describe the synthesis-degradation kinetics of PLFA from different microbial origins. We found that the PLFA formation generally reaches its maximal abundance within 7 days (except for PLFA from actinomycetes). The SUM- and wheat residue-derived C fluxes, as well as their PLFA profiles, were inconsistently impacted by the residue quality or the tillage regime over the incubation period. Specifically, the abundances of residue-derived CO2 and PLFAs significantly decreased in the following order: grains > leaves > roots. However, those abundances derived from SUM were the lowest with the leaf residue treatments. Residue-derived PLFA patterns were highly influenced by fungi and G bacteria, while G bacterial and actinomycete PLFAs were preferentially linked to extant SUM mineralization. Compared to the residue-derived counterparts, the SUM-derived microbes were characterized by higher G(+)/G bacteria and cy17:01C16:1 omega 7c ratios, as well as lower fungi/bacteria PLFA ratios. Such distinction between residue and SUM was also evidenced by the contrasting tillage effects on C mineralization and the ratios of cy17:01C16:1 omega 7c and fungal/G bacterial PLFA. Our study provides evidence with important implications for adapting the microbial-mediated processes of soil C management through residue quality control. (C) 2015 Elsevier B.V. All rights reserved.