Department of Microbiology, Oregon State University, Corvallis, Oregon, USA.
Instituto Mediterráneo de Estudios Avanzados (CSIC-UIB), Balearic Islands, Palma de Mallorca, Spain.
Appl Environ Microbiol. 2021 Jan 15;87(3). doi: 10.1128/AEM.02326-20.
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 shoots with and without an intact rhizosphere and cultivated plants for 4 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 14 days. Conspicuously, changes in the microbial communities of washed transplants corresponded with changes in the 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 resilience of the seagrass microbiome after disturbance. Consideration of the microbiome will have meaningful implications for habitat restoration practices. 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 with and without intact rhizospheres and tracking microbiome and plant morphological recovery over 4 weeks. We found the seagrass microbiome to be resilient to transplantation disturbance, recovering after 14 days. Additionally, microbiome recovery was linked with seagrass morphology, coinciding with increases in the rhizosphere sediment mass and root biomass. The results of this study can be used to include microbiome responses in informing future restoration work.
海草与其微生物组可以形成互利共生关系，促进能量、营养物质和激素的交换，最终影响植物的抗应激能力。然而，对于干扰后地下海草微生物组的群落演替及其在植物移植后的恢复中的潜在作用，我们知之甚少。我们移植了带有和不带有完整根际的海草芽，并在 4 周内培养植物，同时描述微生物组的恢复及其对植物特征的影响。根际和根微生物组在组成上存在差异，可能代表离散的微生物小生境。此外，移植后的洗根和移栽的微生物组最初与移栽的微生物组不同，并在 14 天内恢复到未受干扰的状态。值得注意的是，洗根移植后微生物群落的变化与根际沉积物质量和根生物量的变化相对应，突出了植物、其微生物组和环境之间关系的强度和响应性质。随着时间的推移，丰富的潜在共生微生物包括那些在根际环境中循环和转化硫、氮和植物衍生碳的微生物。这些发现强调了干扰后海草微生物组的重要性和恢复能力。考虑微生物组将对生境恢复实践产生有意义的影响。海草是全球范围内正在减少的重要沿海物种，移植可以用来对抗这些减少。然而，海草根际和根（微生物组）相关的细菌群落通常在移植前受到干扰或完全去除。海草微生物组通过代谢物、营养物质和植物激素的交换使海草受益，并通过循环硫、氮和碳为海草草地的生态系统服务做出贡献。本实验通过移植带有和不带有完整根际的海草，跟踪微生物组和植物形态恢复 4 周，旨在描述海草地下微生物组的重要性和恢复能力。我们发现海草微生物组对移植干扰具有恢复能力，在 14 天后恢复。此外，微生物组的恢复与海草形态有关，与根际沉积物质量和根生物量的增加同时发生。本研究的结果可用于在未来的恢复工作中纳入微生物组的响应。
