Recovery and Community Succession of the Zostera marina Rhizobiome After Transplantation

Seagrasses can form mutualisms with their microbiomes that facilitate the exchange of energy sources, nutrients, and hormones, and ultimately impact plant stress resistance. Little is known about community succession within the belowground seagrass microbiome after disturbance and its potential role in the plant’s recovery after transplantation. We transplanted Zostera marina shoots with and without an intact rhizosphere, and cultivated plants for four weeks while characterizing microbiome recovery and effects on plant traits. Rhizosphere and root microbiomes were compositionally distinct, likely representing discrete microbial niches. Furthermore, microbiomes of washed transplants were initially different from those of sod transplants, and recovered to resemble an undisturbed state within fourteen days. Conspicuously, changes in microbial communities of washed transplants corresponded with changes in rhizosphere sediment mass and root biomass, highlighting the strength and responsive nature of the relationship between plants, their microbiome, and the environment. Potential mutualistic microbes that were enriched over time include those that function in the cycling and turnover of sulfur, nitrogen, and plant-derived carbon in the rhizosphere environment. These findings highlight the importance and resiliency of the seagrass microbiome after disturbance. Consideration of the microbiome will have meaningful implications on habitat restoration practices. Importance Seagrasses are important coastal species that are declining globally, and transplantation can be used to combat these declines. However, the bacterial communities associated with seagrass rhizospheres and roots (the microbiome) are often disturbed or removed completely prior to transplantation. The seagrass microbiome benefits seagrasses through metabolite, nutrient, and phytohormone exchange, and contributes to the ecosystem services of seagrass meadows by cycling sulfur, nitrogen, and carbon. This experiment aimed to characterize the importance and resilience of the seagrass belowground microbiome by transplanting Zostera marina with and without intact rhizospheres and tracking microbiome and plant morphological recovery over four weeks. We found the seagrass microbiome to be resilient to transplantation disturbance, recovering after fourteen days. Additionally, microbiome recovery was linked with seagrass morphology, coinciding with increases in rhizosphere sediment mass and root biomass. Results of this study can be used to include microbiome responses in informing future restoration work.

Recovery and Community Succession of the Zostera marina Rhizobiome After Transplantation

Seagrasses can form mutualisms with their microbiomes that facilitate the exchange of energy sources, nutrients, and hormones, and ultimately impact plant stress resistance. Little is known about community succession within the belowground seagrass microbiome after disturbance and its potential role in the plant’s recovery after transplantation. We transplanted Zostera marina shoots with and without an intact rhizosphere and cultivated plants for four weeks while characterizing microbiome recovery and effects on plant traits. Rhizosphere and root microbiomes were compositionally distinct, likely representing discrete microbial niches. Furthermore, microbiomes of washed transplants were initially different from those of sod transplants, and recovered to resemble an undisturbed state within fourteen days. Conspicuously, changes in microbial communities of washed transplants corresponded with changes in rhizosphere sediment mass and root biomass, highlighting the strength and responsive nature of the relationship between plants, their microbiome, and the environment. Potential mutualistic microbes that were enriched over time include those that function in the cycling and turnover of sulfur, nitrogen, and plant-derived carbon in the rhizosphere environment. These findings highlight the importance and resiliency of the seagrass microbiome after disturbance. Consideration of the microbiome will have meaningful implications on habitat restoration practices.ImportanceSeagrasses are important coastal species that are declining globally, and transplantation can be used to combat these declines. However, the bacterial communities associated with seagrass rhizospheres and roots (the microbiome) are often disturbed or removed completely prior to transplantation. The seagrass microbiome benefits seagrasses through metabolite, nutrient, and phytohormone exchange, and contributes to the ecosystem services of seagrass meadows by cycling sulfur, nitrogen, and carbon. This experiment aimed to characterize the importance and resilience of the seagrass belowground microbiome by transplanting Zostera marina with and without intact rhizospheres and tracking microbiome and plant morphological recovery over four weeks. We found the seagrass microbiome to be resilient to transplantation disturbance, recovering after fourteen days. Additionally, microbiome recovery was linked with seagrass morphology, coinciding with increases in rhizosphere sediment mass and root biomass. Results of this study can be used to include microbiome responses in informing future restoration work.

Impacting Microbial Communities and Absorbing Pollutants by Canna Indica and Cyperus Alternifolius in a Full-Scale Constructed Wetland System

Wetland plants that cover the wetlands play an important role in reducing pollutants. The aim of this study was to investigate the effect of two plant species on microbial communities and nitrogen-removal genes and to evaluate the contributions of absorbing pollutants by Canna indica (CI) and Cyperus alternifolius (CA) to the removal performance in both a vertical subsurface flow constructed wetland and a horizontal subsurface flow constructed wetland, which were part of a full-scale hybrid constructed wetland system. The microbial assemblages were determined using 16S rRNA high-throughput sequencing. Results showed that the presence of CI and CA positively affected microbial abundance and community in general and which was positive for the total bacteria and ammonia nitrogen removal in the CWs. The higher abundance of Nitrospirae appeared in the non-rhizosphere sediment (NRS) than that in the rhizosphere sediment (RS). More denitrification genes were found in NRS than in RS. The copy numbers of narG, nirS and nosZ genes for CA were higher than those for CI. Wetland plant species can significantly (P < 0.05) affect the distribution of microbial communities in RS. Plant selection is important to promote the development of microbial communities with a more active and diverse catabolic capability and the contribution of plant absorption to the overall removal rate of wetland system can be neglected.