Niche Differentiation in the Composition, Predicted Function, and Co-occurrence Networks in Bacterial Communities Associated With Antarctic Vascular Plants

Frontiers in Microbiology

Michael J. Sadowsky¹  María L. Mora³  Milko A. Jorquera³  Paola Duran³  Jacquelinne J. Acuña³  Nitza G. Inostroza³  Qian Zhang⁴ 

[1] Department of Soil, Water, and Climate, and Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, United States;Laboratorio de Ecología Microbiana Aplicada (EMALAB), Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile;Network for Extreme Environment Research (NEXER), Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Temuco, Chile;The BioTechnology Institute, University of Minnesota, St Paul, MN, United States;

关键词: bacterial community;    Colobanthus quitensis;    Deschampsia antarctica;    endosphere;    phyllosphere;    rhizosphere;   

DOI  :  10.3389/fmicb.2020.01036

来源: DOAJ

【 摘 要 】

Climate change directly affecting the Antarctic Peninsula has been reported to induce the successful colonization of ice-free lands by two Antarctic vascular plants (Deschampsia antarctica and Colobanthus quitensis). While studies have revealed the importance of microbiota for plant growth and stress tolerance in temperate climates, the role that plant-associated microbes play in the colonization of ice-free lands remains unknown. Consequently, we used high-throughput DNA sequence analyses to explore the composition, predicted functions, and interactive networks of plant-associated microbial communities among the rhizosphere, endosphere, and phyllosphere niches of D. antarctica and C. quitensis. Here we report a greater number of operational taxonomic units (OTUs), diversity, and richness in the microbial communities from the rhizosphere, relative to endosphere and phyllosphere. While taxonomic assignments showed greater relative abundances of Proteobacteria, Bacteroidetes, and Actinobacteria in plant niches, principal coordinate analysis revealed differences among the bacterial communities from the other compartments examined. More importantly, however, our results showed that most of OTUs were exclusively found in each plant niche. Major predicted functional groups of these microbiota were attributed to heterotrophy, aerobic heterotrophy, fermentation, and nitrate reduction, independent of plant niches or plant species. Co-occurrences network analyses identified 5 (e.g., Microbacteriaceae, Pseudomonaceae, Lactobacillaceae, and Corynebacteriaceae), 23 (e.g., Chitinophagaceae and Sphingomonadaceae) and 7 (e.g., Rhodospirillaceae) putative keystone taxa present in endosphere, phyllosphere, and rhizosphere, respectively. Our results revealed niche differentiation in Antarctic vascular plants, highlighting some putative microbial indicators and keystone taxa in each niche. However, more studies are required to determine the pivotal role that these microbes play in the successful colonization of ice-free lands by Antarctic plants.

【 授权许可】

Unknown