scholarly journals Isolation of Endophytic Salt-Tolerant Plant Growth-Promoting Rhizobacteria From Oryza sativa and Evaluation of Their Plant Growth-Promoting Traits Under Salinity Stress Condition

2021 ◽  
Vol 5 ◽  
Author(s):  
Tania Akter Jhuma ◽  
Jannatul Rafeya ◽  
Shahnaz Sultana ◽  
Mohammad Tariqur Rahman ◽  
Muhammad Manjurul Karim
Keyword(s):  
Oryza Sativa ◽  
Plant Growth ◽  
Salinity Stress ◽  
Growth Promotion ◽  
Restriction Analysis ◽  
Plant Growth Promoting Rhizobacteria ◽  
Microtiter Plate Assay ◽  
Plant Growth Promoting ◽  
Pgp Activities ◽  
Growth Promoting

The application of plant growth-promoting rhizobacteria (PGPR) as vital components for plant growth promotion against biotic and abiotic stresses could be a promising strategy to improve crop production in areas vulnerable to increasing salinity. Here, we isolated Seventy-five endophytic bacteria from roots of healthy Oryza sativa grown in a saline environment of the southern coastal region of Bangladesh. The endophytes in a culture of ~108 CFU/ml showed arrays of plant growth-promoting (PGP) activities: phytohormone (Indole acetic acid) production (1.20–60.13 μg/ ml), nutrient (phosphate) solubilization (0.02–1.81 μg/ml) and nitrogen fixation (70.24–198.70 μg/ml). Four genomically diverse groups were identified namely, Enterobacter, Achromobacter, Bacillus, and Stenotrophomonas using amplified ribosomal DNA restriction analysis followed by their respective 16S rDNA sequence analyses with that of the data available in NCBI GenBank. These four specific isolates showed tolerance to NaCl ranging from 1.37 to 2.57 mol/L in the nutrient agar medium. Under a 200 mmol/L salt stress in vitro, the bacteria in a culture of 108 CFU/ml exhibited competitive exopolysaccharide (EPS) production: Stenotrophomonas (65 μg/ml) and Bacillus (28 μg/ml), when compared to the positive control, Pseudomonas spp. (23.65 μg/ml), a phenomenon ably supported by their strong biofilm-producing abilities both in a microtiter plate assay, and in soil condition; and demonstrated by images of the scanning electron microscope (SEM). Overall, the isolated endophytic microorganisms revealed potential PGP activities that could be supported by their biofilm-forming ability under salinity stress, thereby building up a sustainable solution for ensuring food security in coastal agriculture under changing climate conditions.

scholarly journals Production of Plant Beneficial and Antioxidants Metabolites by Klebsiella variicola under Salinity Stress

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1894
Author(s):  
Supriya P. Kusale ◽  
Yasmin C. Attar ◽  
R. Z. Sayyed ◽  
Roslinda A. Malek ◽  
Noshin Ilyas ◽  
...  
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Beneficial Effects ◽  
Wide Range ◽  
Antioxidant Metabolites ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
And Oxidative Stress

Bacteria that surround plant roots and exert beneficial effects on plant growth are known as plant growth-promoting rhizobacteria (PGPR). In addition to the plant growth-promotion, PGPR also imparts resistance against salinity and oxidative stress and needs to be studied. Such PGPR can function as dynamic bioinoculants under salinity conditions. The present study reports the isolation of phytase positive multifarious Klebsiella variicola SURYA6 isolated from wheat rhizosphere in Kolhapur, India. The isolate produced various plant growth-promoting (PGP), salinity ameliorating, and antioxidant traits. It produced organic acid, yielded a higher phosphorous solubilization index (9.3), maximum phytase activity (376.67 ± 2.77 U/mL), and copious amounts of siderophore (79.0%). The isolate also produced salt ameliorating traits such as indole acetic acid (78.45 ± 1.9 µg/mL), 1 aminocyclopropane-1-carboxylate deaminase (0.991 M/mg/h), and exopolysaccharides (32.2 ± 1.2 g/L). In addition to these, the isolate also produced higher activities of antioxidant enzymes like superoxide dismutase (13.86 IU/mg protein), catalase (0.053 IU/mg protein), and glutathione oxidase (22.12 µg/mg protein) at various salt levels. The isolate exhibited optimum growth and maximum secretion of these metabolites during the log-phase growth. It exhibited sensitivity to a wide range of antibiotics and did not produce hemolysis on blood agar, indicative of its non-pathogenic nature. The potential of K. variicola to produce copious amounts of various PGP, salt ameliorating, and antioxidant metabolites make it a potential bioinoculant for salinity stress management.

Rhizobium leguminosarum as a plant growth-promoting rhizobacterium: direct growth promotion of canola and lettuce

1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Direct Growth ◽  
Early Seedling ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.

Colonization and growth promotion of outplanted spruce seedlings pre-inoculated with plant growth-promoting rhizobacteria in the greenhouse

2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway
Keyword(s):  
Plant Growth ◽  
Seedling Growth ◽  
Picea Glauca ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Population Declines ◽  
Growth Responses ◽  
Relative Growth Rates ◽  
Plant Growth Promoting ◽  
Growth Promoting

Seeds of two hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) ecotypes were inoculated with one of six plant growth-promoting rhizobacteria (PGPR) strains previously shown to be able to stimulate spruce growth in controlled environments. The resulting seedlings were grown in the greenhouse for 17 weeks before outplanting at four reforestation sites. Inoculation with five of the six strains caused significant seedling growth promotion in the greenhouse, which necessitated analysis of relative growth rates (RGR) to evaluate seedling performance in the field. Four months after outplanting, most strains enhanced spruce shoot or root RGRs in the field, but seedling growth responses were strain specific. For example, Pseudomonas strain Ss2-RN significantly increased both shoot and root RGRs by 10-234% at all sites, but increases of 28-70% were most common. In contrast, Bacillus strain S20-R was ineffective at all outplanting sites. In addition, seedlings inoculated with four of the six strains had significantly less shoot injury than control seedlings at all sites. Evaluation of root colonization by PGPR indicated that bacterial population declines were not related to spruce growth response variability in the field. Our results indicate that once plant growth promotion is induced in the greenhouse, seedling RGR can increase by more than 100% during the first growing season in the field. However RGR increases of 21-47% were more common and may be more representative of the magnitude of biomass increases that can result from PGPR inoculation.

scholarly journals Characterization of Selected Plant Growth-Promoting Rhizobacteria and Their Non-Host Growth Promotion Effects

2021 ◽  
Author(s):  
Di Fan ◽  
Donald L. Smith
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Content Type ◽  
Host Growth ◽  
Plant Growth Promoting ◽  
Growth Promoting

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .

scholarly journals Impact of Plant Growth Promoting Rhizobacteria in Sustainable Agriculture: An Important Natural Resource for Crop Improvement

2019 ◽  
Vol 5 (03) ◽  
pp. 210-214
Author(s):  
Debnirmalya Gangopadhyay ◽  
Ashmita Ghosh
Keyword(s):  
Plant Growth ◽  
Sustainable Agriculture ◽  
Crop Yields ◽  
Growth Promotion ◽  
Crop Improvement ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Increasing Demand ◽  
Environmentally Sound

It is usually admitted that the chemical fertilizers and pesticides used in modern agriculture create a real environmental and public health problems. The increasing demand for production with a significant reduction of synthetic fertilizers and pesticides use is a big challenge nowadays. The use of plant growth promoting rhizobacteria or PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. They play an important role to increase in soil fertility, plant growth promotion and suppression of phytopathogens for development of ecofriendly sustainable agriculture. In view of the latest advances in PGPR biotechnology, this paper proposes to do the review on PGPR in rhizosphere and describes the different mechanisms used by PGPR to promote the plants growth and health. In prospect to a healthy and sustainable agriculture, the PGPR approach revealed as one of the best ecofriendly alternatives.

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