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.
Bibliographical noteFunding Information:
Funding. This study was funded by Chilean Antarctic Institute (INACH) project code RT_02_16. The authors also thanks to financial support by The National Fund for Scientific and Technological Development (FONDECYT) projects no. 1160302 (to MJ), 11160112 (to JA), and 1181050 (to MM), by INACH project RT_06_17 (to MJ and PD), by SATREPS-MACH JPMJSA1705 by JST/JICA Japan (to MJ and JA), by the Minnesota Corn Research & Promotion Council (to QZ), and by the Minnesota Agricultural Experiment Station (to MS).
© Copyright © 2020 Zhang, Acuña, Inostroza, Duran, Mora, Sadowsky and Jorquera.
- Colobanthus quitensis
- Deschampsia antarctica
- bacterial community
PubMed: MeSH publication types
- Journal Article