Spatiotemporal organization of the rhizosphere microbiome shaped by external drivers

外部驱动因素塑造的根际微生物组的时空组织

• 批准号: 403637238
• 负责人: Professorin Dr. Kornelia Smalla
• 金额: --
• 依托单位: Institut für Epidemiologie und Pathogendiagnostik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/403637238?language=en
• 关键词: Spatiotemporal; organization; rhizosphere; microbiome; shaped

The rhizosphere microbiome plays an important role for soil ecosystem functions and plant growth and health. Self-organization of the rhizosphere arises from feedback loops between root, microbiome and soil. In phase I of the SPP2089 we aimed to unravel major external drivers shaping the spatial and temporal rhizosphere microbiome patterns. We investigated the microbiome associated with the rhizosphere of two maize genotypes (wild type (WT) and root hair defective mutant (rth3)) in two distinct soil substrates (loam (L) and sand (S)) in central soil column experiments in a growth chamber (SCE) and a soil plot experiment in the field (SPE). Sequence analysis of 16S rRNA gene and ITS amplicons from total community (TC)-DNAs revealed that the soil substrate was the strongest driver shaping the maize rhizosphere microbiome followed by soil depth and maize genotype (SCE and SPE). Unexpectedly, the presence of maize root hairs had only minor effects on the rhizosphere microbiome, in SCE and SPE. In phase II we will continue to address the hypotheses 1 and 4 and novel questions II, III and IV of the SPP2089 in more detail, to unravel spatial organization of the rhizosphere microbiome of maize depending on the soil texture and the presence of external drivers (inoculation of a consortium of beneficial microorganisms [BMs], drought conditions). We will participate in the central experiments performed both at lab (SCE_Drought) and field (SPE_BBCH19) scale, and will carry out central satellite experiments using pots and rhizoboxes (RB_Drought_BM). We hypothesize that the presence of root hairs and the inoculation of a consortium of BMs will be more important for maize growth performance and rhizosphere/rhizoplane microbiome under drought conditions. The role of root hair and spatial pattern (root tip, root base and different soil depths) of the rhizosphere microbiome of maize affected by drought and/or inoculated BMs will be investigated in a polyphasic and interdisciplinary approach (MiSeq sequencing of amplicons from TC-DNAs, qPCR, CLSM, selective plating and Winrhizo performed by our group). For the SPE_BBCH19, we will participate in the complex sampling to test the following hypotheses: (i) After four years of maize growth under field conditions soil substrate, depth and plant genotype will still be the main drivers shaping the rhizosphere microbiome and (ii) Maize root residues and deposits resulting from previous cropping will be degraded in a soil substrate-dependent manner and result in a build-up of taxa contributing to replant depression and microbial dysbiosis, using the MisSeq amplicon sequencing and qPCR. Applying the concept of self-organization to the rhizosphere and unique interdisciplinary approaches used to investigate the central experiments will enable us to gain a better understanding of the spatiotemporal rhizosphere microbiome patterns and how they are influenced by external drivers.

根际微生物组对土壤生态系统功能和植物生长与健康起着重要作用。根际的自组织来自于根、微生物组和土壤之间的反馈回路。在SPP 2089的第一阶段，我们的目标是揭示形成空间和时间根际微生物组模式的主要外部驱动因素。我们调查了与两种玉米基因型（野生型（WT）和根毛缺陷突变体（rth 3））在两种不同的土壤基质（壤土（L）和沙子（S））的根际微生物组在中央土柱实验中的生长室（SCE）和土壤小区实验在外地（SPE）。16 S rRNA基因和ITS扩增产物的序列分析表明，土壤基质是形成玉米根际微生物组的最强驱动力，其次是土壤深度和玉米基因型（SCE和SPE）。出乎意料的是，在SCE和SPE中，玉米根毛的存在对根际微生物组只有很小的影响。在第二阶段，我们将继续更详细地解决SPP 2089的假设1和4以及新问题II，III和IV，以揭示玉米根际微生物组的空间组织，这取决于土壤质地和外部驱动因素的存在（接种有益微生物[BM]，干旱条件）。我们将参与在实验室（SCE_Drought）和田间（SPE_BBCH19）规模进行的中心实验，并将使用盆栽和根箱（RB_Drought_BM）进行中心卫星实验。我们推测，根毛的存在和接种的一个财团的BM将是更重要的玉米生长性能和根际/根面微生物组在干旱条件下。受干旱和/或接种BM影响的玉米根际微生物组的根毛和空间模式（根尖，根基部和不同土壤深度）的作用将以多相和跨学科的方法进行研究（来自TC-DNA的扩增子的MiSeq测序，qPCR，CLSM，选择性平板接种和Winrhizo由我们的小组进行）。对于SPE_BBCH 19，我们将参与复杂抽样以检验以下假设：（i）玉米在田间土壤基质条件下生长四年后，深度和植物基因型仍将是形成根际微生物组的主要驱动因素;（ii）前茬玉米根残留物和沉积物将以土壤基质依赖的方式降解，并导致构建-使用MisSeq扩增子测序和qPCR，研究了导致再植抑郁和微生物生态失调的分类群。将自组织的概念应用于根际和独特的跨学科方法来研究中心实验将使我们能够更好地了解根际微生物组的时空模式以及它们如何受到外部驱动因素的影响。