Journal of Siberian Federal University. Biology / Plant Growth Promoting Activity and Metal Tolerance of Bacteria Isolated from Rhizosphere of the Orchid Epipactis atrorubens Growing on Serpentine Substrates of the Middle Urals

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Issue
Journal of Siberian Federal University. Biology. 2022 15 (3)
Authors
Voropaeva, Olga V.; Borisova, Galina G.; Maleva, Maria G.; Podstavkina, Anastasia V.; Ermoshin, Alexander A.; Tugbaeva, Anastasia S.; Filimonova, Elena I.
Contact information
Borisova, Galina G.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; ORCID: 0000-0001-6663-9948; Maleva, Maria G.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; ; ORCID: 0000-0003-1686-6071; Podstavkina, Anastasia V.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; ORCID: 0000-0002-1530-5291; Ermoshin, Alexander A.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; Inner Mongolia Academy of Agriculture and Animal Husbandry Science Hohhot, China; ORCID: 0000-0003-2784-4898; Tugbaeva, Anastasia S.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; ORCID: 0000-0001-9231-3650; Filimonova, Elena I.: Ural Federal University named after the first President of Russia B. N. Yeltsin Ekaterinburg, Russian Federation; ORCID: 0000-0001-6937-0139
Keywords
Orchidaceae; Orchidaceae; dark-red helleborine; rhizospheric bacteria; serpentine dumps; technogenic substrates; heavy metals; plant growth promoting activity; 16S rRNA gene sequencing
Abstract

The article presents data obtained in the study of bacteria isolated from the rhizosphere of the orchid Epipactis atrorubens (Hoffm.) Besser. Analysis was carried out to compare some morphological, physiological, and biochemical characteristics of plant rhizobacteria growing on serpentine rocks in two biotopes: in the natural forest community (control habitat) and on the asbestos mine dump (the Sverdlovsk region, Middle Urals). An assessment of the plant growth promoting (PGP) activity of the isolated strains did not show significant differences in the ability of rhizobacteria to synthesize indol‑3-acetic acid (IAA) and solubilize phosphates between the study sites. However, the proportion of isolates capable of nitrogen fixation was higher in the rhizosphere of E. atrorubens growing on the dump compared to the control habitat. The tolerance of isolates to heavy metals was assessed by the maximum metal concentration (400, 600, and 1000 mg/L, respectively, for Ni, Cu, and Zn) at which bacterial growth was observed. Rhizobacteria from the dump were found to be more resistant to elevated concentrations of metals compared to their counterparts from the natural forest community. The molecular genetic analysis of isolates with the highest PGP‑activity (IAA >1.0 mg/L; PO4 3- >50.0 mg/L) revealed that most of the E. atrorubens rhizobacteria in both habitats belonged to the genera Buttiauxella and Pseudomonas. In model experiments, the PGP ability of four selected strains was tested on zinnia seeds. Seed inoculation with Pseudomonas sp. and Buttiauxella sp. did not have any significant effect on their germination; however, Buttiauxella sp. contributed to the increase in the length of seedlings compared with the control (by 25 %, on average). It has been suggested that the selected isolates of E. atrorubens rhizobacteria, due to their growth promoting activity and metal tolerance, can facilitate naturalization of the orchid in an industrially disturbed area

Pages
297–313
DOI
10.17516/1997-1389-0389
Paper at repository of SibFU
https://elib.sfu-kras.ru/handle/2311/149174

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