Salt Marsh Elevation Drives Root Microbial Composition of the Native Invasive Grass Elytrigia atherica

Abstract

Elytrigia atherica is a native invasive plant species whose expansion on salt marshes is attributed to genotypic and phenotypic adaptations to non-ideal environmental conditions, forming two ecotypes. It is unknown how E. atherica–microbiome interactions are contributing to its adaptation. Here we investigated the effect of sea-water flooding frequency and associated soil (a)biotic conditions on plant traits and root-associated microbial community composition and potential functions of two E. atherica ecotypes. We observed higher endomycorrhizal colonization in high-elevation ecotypes (HE, low inundation frequency), whereas low-elevation ecotypes (LE, high inundation frequency) had higher specific leaf area. Similarly, rhizosphere and endosphere bacterial communities grouped according to ecotypes. Soil ammonium content and elevation explained rhizosphere bacterial composition. Around 60% the endosphere amplicon sequence variants (ASVs) were also found in soil and around 30% of the ASVs were ecotype-specific. The endosphere of HE-ecotype harbored more unique sequences than the LE-ecotype, the latter being abundant in halophylic bacterial species. The composition of the endosphere may explain salinity and drought tolerance in relation to the local environmental needs of each ecotype. Overall, these results suggest that E. atherica is flexible in its association with soil bacteria and ecotype-specific dissimilar, which may enhance its competitive strength in salt marshes.

Genetically Modified Sugarcane Intercropping Soybean Impact on Rhizosphere Bacterial Communities and Co-occurrence Patterns

“…Analysis of similarity (ANOSIM) was used to determine the significance of differences in the bacterial community structure under different planting patterns. The correlation between the host root biomass and the rhizosphere compositional similarity was determined using the Mantel test implemented in the Vegan package in R ( Hernández et al, 2020 ).…”

Seasonal and Zonal Succession of Bacterial Communities in North Sea Salt Marsh Sediments

“…Our finding that the community composition changes along the land–sea transition zone is in accordance with previous studies on salt marsh microbial communities from the North Sea Islands of Spiekeroog and Schiermonnikoog. While the abundance patterns found in our study differ for some taxa, zonal successions between the upper and lower SM [ 26 ] and between the lower SM and the pioneer zone were detected as well [ 28 ]. A study of a salt marsh chronosequence revealed that a bacterial community composition is strongly associated with the successional stages of the salt marsh and also correlates with short-term seasonal changes in environmental parameters [ 32 ].…”

“…While some of the zonation-relevant variables are well described and similar between distant locations, other factors are still not fully understood [ 12 , 55 , 56 ]. However, the co-occurrence of certain bacterial taxa and the specific vegetation of salt marshes hints towards a tight interaction [ 26 , 57 , 58 ]. To what extent a bacterial community composition is a result of the environmental conditions or is a shaping variable within the salt marsh environments remains to be elucidated.…”

“…Although extreme events such as oil spills and storms or high levels of eutrophication have been shown to drastically influence the natural salt marsh plant and microbe communities [ 23 , 24 ], bacterial communities appear to be generally resistant to large-scale compositional shifts [ 25 ]. Comparisons of bacterial communities between salt marsh zones of the same region have shown that differences even occur between locations of high and low inundation frequencies [ 26 , 27 ], and between the lower SM and the pioneer zone [ 28 , 29 ]. The prevalent plant community, stage of succession, soil organic matter contents, as well as phosphorous and nitrogen concentrations, have been identified to contribute to the succession of the bacterial communities.…”

Fungal Biodiversity in Salt Marsh Ecosystems

“…Bacterial communities are the major decomposers in the latter stage of decomposition [ 27 , 28 ]. Studies in salt marsh ecosystems not only consider microbial activity and the recycling of nutrients, but also bacterial [ 29 , 30 ] and fungal diversity [ 20 , 31 , 32 ].…”