Effects of Elevated Atmospheric CO2 on Microbial Community Structure at the Plant-Soil Interface of Young Beech Trees (Fagus sylvatica L.) Grown at Two Sites with Contrasting Climatic Conditions
Effects of Elevated Atmospheric CO2 on Microbial Community Structure at the Plant-Soil Interface of Young Beech Trees (Fagus sylvatica L.) Grown at Two Sites with Contrasting Climatic Conditions
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DOI：
10.1007/s00248-014-0527-x
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发表时间：
2015-05-01
影响因子：
3.6
通讯作者：
Schloter, Michael
中科院分区：
文献类型：
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作者：
Gschwendtner, Silvia;Leberecht, Martin;Schloter, Michael
土壤微生物群落对大气 CO2 浓度升高 (eCO(2)) 的反应主要通过 CO2 诱导的植物生长刺激间接发生，导致根际沉积和植物凋落物发生量和质的变化。为了深入了解 eCO(2) 对植物-土壤界面微生物群落结构的短期、特定地点影响，来自两个相对山坡、具有对比气候条件的山毛榉幼树 (Fagus sylvatica L.) 在温室中环境二氧化碳浓度 (360 ppm) 下进行培养。收获前一周，一半的树木在 eCO(2) (1,100 ppm) 条件下培育 2 天。通过基于 16S 核糖体 RNA (rRNA) 基因的 TRFLP 和 454 焦磷酸测序研究了附着土壤以及根根际复合体 (RRC) 中微生物群落结构的变化。群落概况的多变量分析表明，在常温和高二氧化碳条件下生长的植物之间的微生物群落结构发生了明显的变化，主要是在 RRC 中。 TRFLP 和 454 焦磷酸测序均显示，作为 CO2 富集的响应，微生物多样性和均匀度显着下降。虽然以根瘤菌目为主的 Alphaproteobacteria 在 eCO(2) 下减少，但 Betaproteobacteria（主要是 Burkholderiales）仍未受到影响。相比之下，分别以假单胞菌目和粘球菌目为主的Gammaproteobacteria和Deltaproteobacteria在eCO(2)下增加。在大气CO2富集下，放线菌目的成员增加，而酸杆菌门内的Gp1亚群减少，Gp4和Gp6亚群增加。此外，浮霉菌门和厚壁菌门（主要是芽孢杆菌的成员）在eCO(2)下增加。总体而言，eCO(2) 对土壤微生物群落的影响强度取决于距根部的距离。对于所有接受调查的树木来说，这种效果都是一致的；没有观察到 eCO(2) 对树木起源的特定地点影响。
Soil microbial community responses to elevated atmospheric CO2 concentrations (eCO(2)) occur mainly indirectly via CO2-induced plant growth stimulation leading to quantitative as well as qualitative changes in rhizodeposition and plant litter. In order to gain insight into short-term, site-specific effects of eCO(2) on the microbial community structure at the plant-soil interface, young beech trees (Fagus sylvatica L.) from two opposing mountainous slopes with contrasting climatic conditions were incubated under ambient (360 ppm) CO2 concentrations in a greenhouse. One week before harvest, half of the trees were incubated for 2 days under eCO(2) (1,100 ppm) conditions. Shifts in the microbial community structure in the adhering soil as well as in the root rhizosphere complex (RRC) were investigated via TRFLP and 454 pyrosequencing based on 16S ribosomal RNA (rRNA) genes. Multivariate analysis of the community profiles showed clear changes of microbial community structure between plants grown under ambient and elevated CO2 mainly in RRC. Both TRFLP and 454 pyrosequencing showed a significant decrease in the microbial diversity and evenness as a response of CO2 enrichment. While Alphaproteobacteria dominated by Rhizobiales decreased at eCO(2), Betaproteobacteria, mainly Burkholderiales, remained unaffected. In contrast, Gammaproteobacteria and Deltaproteobacteria, predominated by Pseudomonadales and Myxococcales, respectively, increased at eCO(2). Members of the order Actinomycetales increased, whereas within the phylum Acidobacteria subgroup Gp1 decreased, and the subgroups Gp4 and Gp6 increased under atmospheric CO2 enrichment. Moreover, Planctomycetes and Firmicutes, mainly members of Bacilli, increased under eCO(2). Overall, the effect intensity of eCO(2) on soil microbial communities was dependent on the distance to the roots. This effect was consistent for all trees under investigation; a site-specific effect of eCO(2) in response to the origin of the trees was not observed.