Granzow Sandra, Kaiser Kristin, Wemheuer Bernd, Pfeiffer Birgit, Daniel Rolf, Vidal Stefan, Wemheuer Franziska
Section of Agricultural Entomology, Department of Crop Sciences, University of GöttingenGöttingen, Germany.
Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, University of GöttingenGöttingen, Germany.
Front Microbiol. 2017 May 29;8:902. doi: 10.3389/fmicb.2017.00902. eCollection 2017.
Many bacteria and fungi in the plant rhizosphere and endosphere are beneficial to plant nutrient acquisition, health, and growth. Although playing essential roles in ecosystem functioning, our knowledge about the effects of multiple cropping regimes on the plant microbiome and their interactions is still limited. Here, we designed a pot experiment simulating different cropping regimes. For this purpose, wheat and faba bean plants were grown under controlled greenhouse conditions in monocultures and in two intercropping regimes: row and mixed intercropping. Bacterial and fungal communities in bulk and rhizosphere soils as well as in the roots and aerial plant parts were analyzed using large-scale metabarcoding. We detected differences in microbial richness and diversity between the cropping regimes. Generally, observed effects were attributed to differences between mixed and row intercropping or mixed intercropping and monoculture. Bacterial and fungal diversity were significantly higher in bulk soil samples of wheat and faba bean grown in mixed compared to row intercropping. Moreover, microbial communities varied between crop species and plant compartments resulting in different responses of these communities toward cropping regimes. Leaf endophytes were not affected by cropping regime but bacterial and fungal community structures in bulk and rhizosphere soil as well as fungal community structures in roots. We further recorded highly complex changes in microbial interactions. The number of negative inter-domain correlations between fungi and bacteria decreased in bulk and rhizosphere soil in intercropping regimes compared to monocultures due to beneficial effects. In addition, we observed plant species-dependent differences indicating that intra- and interspecific competition between plants had different effects on the plant species and thus on their associated microbial communities. To our knowledge, this is the first study investigating microbial communities in different plant compartments with respect to multiple cropping regimes using large-scale metabarcoding. Although a simple design simulating different cropping regimes was used, obtained results contribute to the understanding how cropping regimes affect bacterial and fungal communities and their interactions in different plant compartments. Nonetheless, we need field experiments to properly quantify observed effects in natural ecosystems.
植物根际和内生菌中的许多细菌和真菌有利于植物获取养分、保持健康和生长。尽管在生态系统功能中发挥着重要作用，但我们对多种种植制度对植物微生物组及其相互作用的影响的了解仍然有限。在这里，我们设计了一个盆栽实验来模拟不同的种植制度。为此，小麦和蚕豆植株在可控的温室条件下进行单作种植，并采用两种间作制度：行式间作和混合间作。使用大规模代谢条形码分析了土壤和根际土壤以及根和地上植物部分中的细菌和真菌群落。我们检测到不同种植制度之间微生物丰富度和多样性的差异。一般来说，观察到的影响归因于混合间作与行式间作或混合间作与单作之间的差异。与行式间作相比，混合种植的小麦和蚕豆的土壤样本中细菌和真菌多样性显著更高。此外，微生物群落在作物种类和植物器官之间存在差异，导致这些群落对种植制度的反应不同。叶内生菌不受种植制度的影响，但土壤和根际土壤中的细菌和真菌群落结构以及根中的真菌群落结构受到影响。我们进一步记录了微生物相互作用中高度复杂的变化。由于有益作用，与单作相比，间作制度下土壤和根际土壤中真菌和细菌之间的负域间相关性数量减少。此外，我们观察到植物物种依赖性差异，表明植物种内和种间竞争对植物物种有不同影响，进而对其相关微生物群落也有不同影响。据我们所知，这是第一项使用大规模代谢条形码研究不同种植制度下不同植物器官中微生物群落的研究。尽管使用了一个简单的设计来模拟不同的种植制度，但获得的结果有助于理解种植制度如何影响不同植物器官中的细菌和真菌群落及其相互作用。尽管如此，我们需要进行田间实验，以准确量化在自然生态系统中观察到的影响。
