Alkaline soil pH affects bulk soil, rhizosphere and root endosphere microbiomes of plants growing in a Sandhills ecosystem

Abstract

Soil pH is a major factor shaping bulk soil microbial communities. However, it is unclear whether the belowground microbial habitats shaped by plants (e.g. rhizosphere and root endosphere) are also affected by soil pH. We investigated this question by comparing the microbial communities associated with plants growing in neutral and strongly alkaline soils in the Sandhills, which is the largest sand dune complex in the northern hemisphere. Bulk soil, rhizosphere and root endosphere DNA were extracted from multiple plant species and analyzed using 16S rRNA amplicon sequencing. Results showed that rhizosphere, root endosphere and bulk soil microbiomes were different in the contrasting soil pH ranges. The strongest impact of plant species on the belowground microbiomes was in alkaline soils, suggesting a greater selective effect under alkali stress. Evaluation of soil chemical components showed that in addition to soil pH, cation exchange capacity also had a strong impact on shaping bulk soil microbial communities. This study extends our knowledge regarding the importance of pH to microbial ecology showing that root endosphere and rhizosphere microbial communities were also influenced by this soil component, and highlights the important role that plants play particularly in shaping the belowground microbiomes in alkaline soils.

Continuous monocropping highly affect the composition and diversity of microbial communities in peanut (Arachis hypogaea L.)

“…In contrast, unplanted soil is a steady environment with less nutrients for the microbes to prey on. Previously it was reported that assembly of the rhizosphere microbiota was distinct from that of unplanted soil (Lopes et al, 2021). Despite being grown the same peanut genotype ('Huayu22') for all the three years monocropping cycles, some of the OTUs in T1, T2, and T3 rhizosphere communities generated in this project show little to no overlap in their predominant community members (Figure 2a, b, c).…”

Artificial Plantation Responses to Periodic Submergence in Massive Dam and Reservoir Riparian Zones: Changes in Soil Properties and Bacterial Community Characteristics

“…Differences in the rhizosphere, inner root layer, and soil microbial community in different pH ranges affected the microbiome composition. The cation exchange capacity and endophytic fungi also dramatically influence soil microbial community formation [ 65 , 66 ].…”

Shifts in the Rhizosphere and Endosphere Colonizing Bacterial Communities Under Drought and Salinity Stress as Affected by a Biofertilizer Consortium

“…When analyzing each stress and fertilization treatment for each compartment (i.e., endosphere and rhizosphere) separately by cluster analysis, we found that structural shifts in the bacterial community were more pronounced in the endo-than in the rhizosphere, suggesting the former is more sensitive to these treatments. It has been reported that some environmental factors such as the availability of soil nutrients, soil pH, and cation exchange capacity have a strong impact on shaping rhizosphere microbiome composition [24][25][26]. Rhizosphere bacteria may be more exposed to soil variation and stressful conditions than those inside or on roots, and therefore may already be quite stress-tolerant [10,25].…”

“…It has been reported that some environmental factors such as the availability of soil nutrients, soil pH, and cation exchange capacity have a strong impact on shaping rhizosphere microbiome composition [24][25][26]. Rhizosphere bacteria may be more exposed to soil variation and stressful conditions than those inside or on roots, and therefore may already be quite stress-tolerant [10,25]. This may especially be true here, since these bacteria were native to Southern Italy, where the predominant calcareous soil becomes dry in the warmer seasons and pH is slightly alkaline (pH > 8) [18].…”