Bacterial Root Microbiome of Plants Growing in Oil Sands Reclamation Covers

Abstract

Oil sands mining in northern Alberta impacts a large footprint, but the industry is committed to reclaim all disturbed land to an ecologically healthy state in response to environmental regulations. However, these newly reconstructed landscapes may be limited by several factors that include low soil nutrient levels and reduced microbial activity. Rhizosphere microorganisms colonize plant roots providing hosts with nutrients, stimulating growth, suppressing disease and increasing tolerance to abiotic stress. High-throughput sequencing techniques can be used to provide a detailed characterization of microbial community structure. This study used 16S rRNA amplicon sequencing to characterize the bacterial root microbiome associated with annual barley (Hordeum vulgare) and sweet clover (Melilotus albus) growing in an oil sands reclamation area. Our results indicate that Proteobacteria dominated the endosphere, whereas other phyla such as Acidobacteria and Gemmatimonadetes were restricted to the rhizosphere, suggesting that plants have the ability to select for certain soil bacterial consortia. The bacterial community in the endosphere compartments were less rich and diverse compared to the rhizosphere. Furthermore, it was apparent that sweet clover plants were more selective, as the community exhibited a lower richness and diversity compared to barley. Members of the family Rhizobiaceae, such as Sinorhizobium and Rhizobium were mainly associated with clover, whereas Acholeplasma (wall-less bacteria transmitted by insects) was unique to barley. Genera from the Enterobacteriaceae family, such as Yersinia and Lentzea were also mostly detected in barley, while other genera such Pseudomonas and Pantoea were able to successfully colonize both plants. Endophytic bacterial profiles varied within the same plant species at different sampling locations; however, these differences were driven by factors other than slope positions or cover management. Our results suggest that bacterial endophytic communities of plants growing in land reclamation systems are a subset of the rhizosphere community and selection is driven by plant factors.

Drought delays development of the sorghum root microbiome and enriches for monoderm bacteria

“…Plant-associated microbiomes play a role in determining plant fitness ( 1 , 2 ), and it is well established that the composition of the plant microbiome is influenced by many host-associated and environmental factors ( 3 – 12 ). Recent research has demonstrated that changes in soil moisture availability have significant effects on plant-associated microbiomes ( 13 , 14 ).…”

Impact of long-term industrial contamination on the bacterial communities in urban river sediments

“…According to the OTU information, mothur (version v.1.30.1) was used to calculate the alpha diversity index (Chao 1, ACE, Shannon, Simpson) [86], and curves were generated with the R language tool [87]. Beta diversity analysis was represented by Bray-Curtis distance matrices generated from the OTU table, and statistical analysis and mapping was performed with PCoA in R language [88]. The community structure composition of different classification levels (such as phylum, genus and OTU) was obtained by taxonomic analysis.…”

Endophytic Bacterial Community Structure and Function of Herbaceous Plants From Petroleum Hydrocarbon Contaminated and Non-contaminated Sites

“…For both culture-dependent and independent community composition, we found that Gammaproteobacteria, particularly those genera from family Enterobacteriacea dominated the plant endospheric communities regardless of plant host species and contamination. Genera from family Enterobacteriaceae was also found to predominate the endosphere rather than the rhizosphere of plants in Athabasca oilsands reclamation sites (Mitter et al, 2017 ). Gammaproteobacteria was also reported to be predominant in the endosphere of ginseng plants (Khan Chowdhury et al, 2017 ).…”