Distinct Communities of Poplar Endophytes on an Unpolluted and a Risk Element-Polluted Site and Their Plant Growth-Promoting Potential In Vitro

• Published in: Microbial ecology Vol. 75; no. 4; pp. 955 - 969
• Main Authors: Schmidt, C. S., Lovecká, P., Mrnka, L., Vychodilová, A., Strejček, M., Fenclová, M., Demnerová, K.
• Format: Journal Article
• Language: English
• Published: New York Springer Science + Business Media 01-05-2018; Springer US; Springer Nature B.V
• Subjects: Antioxidants; Bacilli; Bacteria; Biodiversity; Biomedical and Life Sciences; Bioremediation; Communities; Ecology; Endophytes; ENVIRONMENTAL MICROBIOLOGY; Fitness; Fungi; Geoecology/Natural Processes; In vitro methods and tests; Life Sciences; Microbial Ecology; Microbiological strains; Microbiology; Mineral nutrients; Nature Conservation; Phosphates; Phytoremediation; Plant growth; Plant growth substances; Plant stress; Polluted environments; Poplar; Risk; Siderophores; Species diversity; Strains (organisms); Water Quality/Water Pollution; Sordariomycetes; Endophytes; Poplar; Risk elements; PGPB; Phytoremediation
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-017-1103-y

Numerous studies demonstrated that endophytic microbes can promote plant growth and increase plant stress resistance. We aimed at isolating poplar endophytes able to increase their hosts’ fitness both in nutrient-limited and polluted environments. To achieve this goal, endophytic bacteria and fungi were isolated from roots and leaves of hybrid poplars (Populus nigra × P. maximowiczii clone Max-4) on an unpolluted and a risk element-polluted site in the Czech Republic and subsequently screened by a number of in vitro tests. Bacterial communities at the unpolluted site were dominated by Gammaproteobacteria with Pseudomonas sp. as the prominent member of the class, followed by Bacilli with prevailing Bacillus sp., whereas Alphaproteobacteria, mostly Rhizobium sp., prevailed at the polluted site. The fungal endophytic community was dominated by Ascomycetes and highly distinct on both sites. Dothideomycetes, mostly Cladosporium, prevailed at the non-polluted site while unclassified Sordariomycetous fungi dominated at the polluted site. Species diversity of endophytes was higher at the unpolluted site. Many tested endophytic strains solubilized phosphate and produced siderophores, phytohormones, and antioxidants. Some strains also exhibited ACC-deaminase activity. Selected bacteria showed high tolerance and the ability to accumulate risk elements, making them promising candidates for use in inocula promoting biomass production and phytoremediation.