Institute of Tropical Plant Sciences and Microbiology, National Cheng Kung University, Tainan, 70101, Taiwan.
Department of Life Sciences, National Cheng Kung University, Tainan, 70101, Taiwan.
Microb Ecol. 2020 Jul;80(1):133-144. doi: 10.1007/s00248-019-01467-8. Epub 2019 Dec 12.
Miscanthus in Taiwan occupies a cline along altitude and adapts to diverse environments, e.g., habitats of high salinity and volcanoes. Rhizospheric and endophytic bacteria may help Miscanthus acclimate to those stresses. The relative contributions of rhizosphere vs. endosphere compartments to the adaptation remain unknown. Here, we used targeted metagenomics to compare the microbial communities in the rhizosphere and endosphere among ecotypes of M. sinensis that dwell habitats under different stresses. Proteobacteria and Actinobacteria predominated in the endosphere. Diverse phyla constituted the rhizosphere microbiome, including a core microbiome found consistently across habitats. In endosphere, the predominance of the bacteria colonizing from the surrounding soil suggests that soil recruitment must have subsequently determined the endophytic microbiome in Miscanthus roots. In endosphere, the bacterial diversity decreased with the altitude, likely corresponding to rising limitation to microorganisms according to the species-energy theory. Specific endophytes were associated with different environmental stresses, e.g., Pseudomonas spp. for alpine and Agrobacterium spp. for coastal habitats. This suggests Miscanthus actively recruits an endosphere microbiome from the rhizosphere it influences.
台湾芒沿海拔形成梯度分布，适应多样的环境，例如高盐度和火山环境。根际和内生细菌可能有助于芒适应这些胁迫。根际和内生区室对适应的相对贡献尚不清楚。在这里，我们使用靶向宏基因组学比较了生活在不同胁迫生境中的中华芒生态型的根际和内生区室中的微生物群落。在内生区室中，变形菌门和放线菌门占主导地位。多样的门构成了根际微生物组，包括在所有生境中都一致存在的核心微生物组。在内生区室中，从周围土壤中定殖的细菌占优势，这表明土壤的再补充随后决定了芒根系中的内生微生物组。在内生区室中，细菌多样性随海拔升高而降低，这可能与根据物种能量理论微生物的限制增加相对应。特定的内生菌与不同的环境胁迫相关，例如，高山环境中的假单胞菌和沿海环境中的根瘤菌。这表明芒从其影响的根际主动招募内生微生物组。
