Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings

Drought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the...

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Main Authors: Alemayehu Getahun, Diriba Muleta, Fassil Assefa, Solomon Kiros
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:International Journal of Microbiology
Online Access:http://dx.doi.org/10.1155/2020/8897998
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author Alemayehu Getahun
Diriba Muleta
Fassil Assefa
Solomon Kiros
author_facet Alemayehu Getahun
Diriba Muleta
Fassil Assefa
Solomon Kiros
author_sort Alemayehu Getahun
collection DOAJ
description Drought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the effect of inoculating Acacia abyssinica seedlings with PGPR isolated from rhizosphere soil of Ethiopia to enhance DS tolerance. The strains were selected based on in vitro assays associated with tolerance to drought and other beneficial traits such as salinity, acidity, temperature, heavy metal tolerances, biofilm formation, and exopolysaccharide (EPS) production. The strains with the best DS tolerance ability were selected for the greenhouse trials with acacia plants. The results indicate that out of 73 strains, 10 (14%) were completely tolerant to 40% polyethylene glycol. Moreover, 37% of the strains were strong biofilm producers, while 66 (90.41%) were EPS producers with a better production in the medium containing sucrose at 28 ± 2°C and pH 7 ± 0.2. Strains PS-16 and RS-79 showed tolerance to 11% NaCl. All the strains were able to grow in wider ranges of pH (4–10) and temperature (15–45°C) and had high tolerance to heavy metals. The inoculated bacterial strains significantly (p≤0.05) increased root and shoot length and dry biomass of acacia plants. One of the strains identified as P. fluorescens strain FB-49 was outstanding in enhancing DS tolerance compared to the single inoculants and comparable to consortia. Stress-tolerant PGPR could be used to enhance acacia DS tolerance after testing other phytobeneficial traits.
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spelling doaj-art-2adf2d894b4445cf9201162c2599fcb12025-08-20T02:04:13ZengWileyInternational Journal of Microbiology1687-918X1687-91982020-01-01202010.1155/2020/88979988897998Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) SeedlingsAlemayehu Getahun0Diriba Muleta1Fassil Assefa2Solomon Kiros3College of Natural Sciences, Addis Ababa University, Addis Ababa, EthiopiaCollege of Natural Sciences, Addis Ababa University, Addis Ababa, EthiopiaCollege of Natural Sciences, Addis Ababa University, Addis Ababa, EthiopiaAddis Ababa Institute of Technology, Addis Ababa University, Addis Ababa, EthiopiaDrought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the effect of inoculating Acacia abyssinica seedlings with PGPR isolated from rhizosphere soil of Ethiopia to enhance DS tolerance. The strains were selected based on in vitro assays associated with tolerance to drought and other beneficial traits such as salinity, acidity, temperature, heavy metal tolerances, biofilm formation, and exopolysaccharide (EPS) production. The strains with the best DS tolerance ability were selected for the greenhouse trials with acacia plants. The results indicate that out of 73 strains, 10 (14%) were completely tolerant to 40% polyethylene glycol. Moreover, 37% of the strains were strong biofilm producers, while 66 (90.41%) were EPS producers with a better production in the medium containing sucrose at 28 ± 2°C and pH 7 ± 0.2. Strains PS-16 and RS-79 showed tolerance to 11% NaCl. All the strains were able to grow in wider ranges of pH (4–10) and temperature (15–45°C) and had high tolerance to heavy metals. The inoculated bacterial strains significantly (p≤0.05) increased root and shoot length and dry biomass of acacia plants. One of the strains identified as P. fluorescens strain FB-49 was outstanding in enhancing DS tolerance compared to the single inoculants and comparable to consortia. Stress-tolerant PGPR could be used to enhance acacia DS tolerance after testing other phytobeneficial traits.http://dx.doi.org/10.1155/2020/8897998
spellingShingle Alemayehu Getahun
Diriba Muleta
Fassil Assefa
Solomon Kiros
Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
International Journal of Microbiology
title Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
title_full Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
title_fullStr Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
title_full_unstemmed Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
title_short Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings
title_sort plant growth promoting rhizobacteria isolated from degraded habitat enhance drought tolerance of acacia acacia abyssinica hochst ex benth seedlings
url http://dx.doi.org/10.1155/2020/8897998
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