Linking carbon and nitrogen availability to microbial phosphorous turnover in different forest soils

将不同森林土壤中碳和氮的有效性与微生物磷周转联系起来

• 批准号: 240847006
• 负责人: Professor Dr. Michael Schloter
• 金额: --
• 依托单位: Abteilung Vergleichende Mikrobiomanalysen (COMI)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240847006?language=en
• 关键词: Linking; carbon; nitrogen; availability; microbial

The development of phosphorous (P) versus nitrogen (N) and carbon (C) contents in soil is reverse. While P concentrations might be high in young ecosystems, given that the bedrock contains P, N and C accumulates over time by initial N2 and CO2 fixation or deposition and later by the turnover of biomass. In contrast to N and C the overall amount of P in soils is stable, if no biomass is removed or no fertilizers are added. Consequently, the addition of nutrients might alter the dynamic of the whole system by increasing or decreasing the microbial activity, changing the microbial community composition or both in combination. Therefore, it is our aim (i) to follow changes in the activity and composition of microbial communities driving P turnover under natural conditions and after altered P, N, C contents and water availability in soil, (ii) to study the interlink between microbial communities driving P turnover to those catalysing major steps in N and C transformation and (iii) to follow spatial distributions of microbes being involved in P turnover and uptake. We hypothesize that the addition of P will not induce significant changes in the P transformation processes, while the addition of N or reduction of C will dramatically alter P transformation processes. To reach the described aims metagenomic and metatranscriptomic approaches will be combined with quantitative PCR and amplicon sequencing to compare the structure, function and abundance of the active and present microbial communities. Therefore, primers will be used for alkaline phosphatase (phoD), phosphonatase (phnX), phytase (HAP) (appA), Pit-Transporter (pitA), Pst-Transporter (pstS) and the quinoprotein glucose dehydrogenase (gcd), which we developed during the 1st phase of the SPP. To follow changes in the active community samples will be taken several times per day to take daily fluctuations of root exudation, light, temperature, humidity etc. into account. Moreover, the presence of alkaline and acidic phosphatases in the rhizosphere will be connected to the presence of different bacteria by applying soil zymography and fluorescence-in situ-hybridization (FISH). By combining those different methods, we hope to better understand the interplay of microbial P, N and C turnover.

土壤中磷(P)与氮(N)和碳(C)含量的发展是相反的。由于基岩中含有磷、氮和碳，随着时间的推移，通过最初的N2和CO2固定或沉积以及后来的生物量周转积累，在年轻的生态系统中P浓度可能很高。与氮和碳相比，如果不去除生物量或不添加肥料，土壤中磷的总量是稳定的。因此，营养物的添加可能通过增加或减少微生物活性，改变微生物群落组成或两者兼而有之来改变整个系统的动态。因此，我们的目标是：(1)在自然条件下以及土壤中P、N、C含量和水分有效性改变后，跟踪驱动P周转的微生物群落活性和组成的变化；(2)研究驱动P周转的微生物群落与催化N和C转化主要步骤之间的相互联系；(3)跟踪参与P周转和吸收的微生物的空间分布。我们假设添加P不会引起P转变过程的显著变化，而添加N或减少C会显著改变P转变过程。为了达到上述目标，宏基因组学和亚转录组学方法将与定量PCR和扩增子测序相结合，比较活跃和现有微生物群落的结构、功能和丰度。因此，引物将用于碱性磷酸酶（phoD）、磷酸化酶（phnX）、植酸酶（HAP） （appA）、Pit-Transporter （pitA）、Pst-Transporter （pstS）和quinoprotein glucose dehydrogenase (gcd)，这是我们在SPP第一阶段开发的。为了跟踪活性群落的变化，我们将每天取几次样品，以考虑根系分泌物、光照、温度、湿度等的日常波动。此外，通过土壤酶谱和荧光原位杂交（FISH）技术，将根际中碱性和酸性磷酸酶的存在与不同细菌的存在联系起来。通过结合这些不同的方法，我们希望更好地了解微生物P、N和C的相互作用。