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Amara Y, Mahjoubi M, Souissi Y, Cherif H, Naili I, ElHidri D, Kadidi I, Mosbah A, Masmoudi AS, Cherif A. Tapping into haloalkaliphilic bacteria for sustainable agriculture in treated wastewater: insights into genomic fitness and environmental adaptation. Antonie Van Leeuwenhoek 2024; 118:1. [PMID: 39269515 DOI: 10.1007/s10482-024-02012-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 08/16/2024] [Indexed: 09/15/2024]
Abstract
The increasing salinity and alkalinity of soils pose a global challenge, particularly in arid regions such as Tunisia, where about 50% of lands are sensitive to soil salinization. Anthropogenic activities, including the use of treated wastewater (TWW) for irrigation, exacerbate these issues. Haloalkaliphilic bacteria, adapted to TWW conditions and exhibiting plant-growth promotion (PGP) and biocontrol traits, could offer solutions. In this study, 24 haloalkaliphilic bacterial strains were isolated from rhizosphere sample of olive tree irrigated with TWW for more than 20 years. The bacterial identification using 16S rRNA gene sequencing showed that the haloalkaliphilic isolates, capable of thriving in high salinity and alkaline pH, were primarily affiliated to Bacillota (Oceanobacillus and Staphylococcus). Notably, these strains exhibited biofertilization and enzyme production under both normal and saline conditions. Traits such as phosphate solubilization, and the production of exopolysaccharide, siderophore, ammonia, and hydrogen cyanide were observed. The strains also demonstrated enzymatic activities, including protease, amylase, and esterase. Four selected haloalkaliphilic PGPR strains displayed antifungal activity against Alternaria terricola, with three showing tolerances to heavy metals and pesticides. The strain Oceanobacillus picturea M4W.A2 was selected for genome sequencing. Phylogenomic analyses indicated that the extreme environmental conditions probably influenced the development of specific adaptations in M4W.A2 strain, differentiating it from other Oceanobacillus picturae strains. The presence of the key genes associated with plant growth promotion, osmotic and oxidative stress tolerance, antibiotic and heavy metals resistance hinted the functional capabilities might help the strain M4W.A2 to thrive in TWW-irrigated soils. By demonstrating this connection, we aim to improve our understanding of genomic fitness to stressed environments. Moreover, the identification of gene duplication and horizontal gene transfer events through mobile genetic elements allow the comprehension of these adaptation dynamics. This study reveals that haloalkaliphilc bacteria from TWW-irrigated rhizosphere exhibit plant-growth promotion and biocontrol traits, with genomic adaptations enabling their survival in high salinity and alkaline conditions, offering potential solutions for soil salinization issues.
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Affiliation(s)
- Yosra Amara
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
- National Agronomy Institute of Tunisia, Avenue Charles Nicolle, 1082, Tunis, Mahrajène, Tunisia
| | - Mouna Mahjoubi
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Yasmine Souissi
- Department of Engineering, German University of Technology in Oman, P.O. Box 1816, 130, Muscat, Oman
| | - Hanene Cherif
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Islem Naili
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Darine ElHidri
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Imen Kadidi
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Amor Mosbah
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Ahmed S Masmoudi
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Ameur Cherif
- Univ. Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia.
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Alarjani KM, Elshikh MS. Plant growth-promoting and biocontrol traits of endophytic Bacillus licheniformis against soft rot causing Pythium myriotylum in ginger plant. J Basic Microbiol 2024; 64:e2300643. [PMID: 38578065 DOI: 10.1002/jobm.202300643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/22/2024] [Accepted: 03/11/2024] [Indexed: 04/06/2024]
Abstract
Bacterial endophytes from plants harbor diverse metabolites that play major roles in biocontrol and improve plant growth. In this study, a total of 12 endophytic bacteria were isolated from the ginger rhizome. The strain K3 was highly effective in preventing mycelia growth of Pythium myriotylum (78.5 ± 1.5% inhibition) in dual culture. The cell-free extract (2.5%) of endophyte K3 inhibited 76.3 ± 4.8% mycelia growth, and 92.4 ± 4.2% inhibition was observed at a 5% sample concentration. The secondary metabolites produced by Bacillus licheniformis K3 showed maximum activity against Pseudomonas syringae (24 ± 1 mm zone of inhibition) and Xanthomonas campestris (28 ± 3 mm zone of inhibition). The strain K3 produced 28.3 ± 1.7 IU mL-1 protease, 28.3 ± 1.7 IU mL-1 cellulase, and 2.04 ± 0.13 IU mL-1 chitinase, respectively. The ginger rhizome treated with K3 in the greenhouse registered 53.8 ± 1.4% soft rot incidence, and the streptomycin-treated pot registered 78.3 ± 1.7% disease incidence. The selected endophyte K3 improved ascorbate peroxidase (1.37 ± 0.009 µmole ASC min-1 mg-1 protein), catalase (8.7 ± 0.28 µmole min-1 mg-1 protein), and phenylalanine ammonia-lyase (26.2 ± 0.99 Umg-1) in the greenhouse. In addition, K3 treatment in the field trial improved rhizome yield (730 ± 18.4 g) after 180 days (p < 0.01). The shoot length was 46 ± 8.3 cm in K3-treated plants, and it was about 31% higher than the control treatment (p < 0.01). The lytic enzyme-producing and growth-promoting endophyte is useful in sustainable crop production through the management of biotic stress.
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Affiliation(s)
- Khaloud Mohammed Alarjani
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed S Elshikh
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
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Arthi R, Parameswari E, Dhevagi P, Janaki P, Parimaladevi R. Microbial alchemists: unveiling the hidden potentials of halophilic organisms for soil restoration. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-33949-9. [PMID: 38877191 DOI: 10.1007/s11356-024-33949-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
Salinity, resulting from various contaminants, is a major concern to global crop cultivation. Soil salinity results in increased osmotic stress, oxidative stress, specific ion toxicity, nutrient deficiency in plants, groundwater contamination, and negative impacts on biogeochemical cycles. Leaching, the prevailing remediation method, is expensive, energy-intensive, demands more fresh water, and also causes nutrient loss which leads to infertile cropland and eutrophication of water bodies. Moreover, in soils co-contaminated with persistent organic pollutants, heavy metals, and textile dyes, leaching techniques may not be effective. It promotes the adoption of microbial remediation as an effective and eco-friendly method. Common microbes such as Pseudomonas, Trichoderma, and Bacillus often struggle to survive in high-saline conditions due to osmotic stress, ion imbalance, and protein denaturation. Halophiles, capable of withstanding high-saline conditions, exhibit a remarkable ability to utilize a broad spectrum of organic pollutants as carbon sources and restore the polluted environment. Furthermore, halophiles can enhance plant growth under stress conditions and produce vital bio-enzymes. Halophilic microorganisms can contribute to increasing soil microbial diversity, pollutant degradation, stabilizing soil structure, participating in nutrient dynamics, bio-geochemical cycles, enhancing soil fertility, and crop growth. This review provides an in-depth analysis of pollutant degradation, salt-tolerating mechanisms, and plant-soil-microbe interaction and offers a holistic perspective on their potential for soil restoration.
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Affiliation(s)
- Ravichandran Arthi
- Department of Environmental Science, Tamil Nadu Agricultural University, Coimbatore, India
| | | | - Periyasamy Dhevagi
- Department of Environmental Science, Tamil Nadu Agricultural University, Coimbatore, India
| | - Ponnusamy Janaki
- Nammazhvar Organic Farming Research Centre, Tamil Nadu Agricultural University, Coimbatore, India
| | - Rathinasamy Parimaladevi
- Department of Bioenergy, Agrl. Engineering College & Research Institute, Tamil Nadu Agricultural University, Coimbatore, India
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Salimian Rizi S, Rezayatmand Z, Ranjbar M, Yazdanpanahi N, Emami- Karvani ZD. The Effect of Bacillus Cereus on the Ion Homeostasis, Growth Parameters, and the Expression of Some Genes of Artemisinin Biosynthesis Pathway in Artemisia Absinthium Under Salinity Stress. IRANIAN JOURNAL OF BIOTECHNOLOGY 2024; 22:e3687. [PMID: 38827342 PMCID: PMC11139441 DOI: 10.30498/ijb.2024.394178.3687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/12/2023] [Indexed: 06/04/2024]
Abstract
Background Soil salinity is a major problem in the world that affects the growth and yield of plants. Application of new and up-to-date techniques can help plants in dealing with salinity stress. One of the approaches for reducing environmental stress is the use of rhizosphere bacteria. Objective The aim of present study was to investigate the effect of the inoculation of Bacillus cereus on physiological and biochemical indicators and the expression of some key genes involved in the Artemisinin biosynthesis pathway in Artemisia absinthium under salinity stress. Materials and Methods The study was conducted using three different salinity levels (0, 75, 150 mM/NaCl) and two different bacterial treatments (i. e, without bacterial inoculation and co-inoculation with B. cereus isolates). The data from the experiments were analyzed using factorial analysis, and the resulting interaction effects were subsequently examined and discussed. Results The results showed that with increasing salinity, root and stem length, root and stem weight, root and stem dry weight, and potassium content were decreased, although the content of sodium was increased. Rhizosphere bacteria increased the contents of Artemisinin, potassium, calcium, magnesium, and iron and the expression of Amorpha-4,11-diene synthase and Cytochrome P450 monooxygenase1 genes as well as the growth indicators; although decreased the sodium content. The highest ADS expression was related to co-inoculation with B. cereus isolates E and B in 150 mM salinity. The highest CYP71AV1 expression was related to co-inoculation with B. cereus isolates E and B in 150 mM salinity. Conclusion These findings showed that the increase in growth indices under salinity stress was probably due to the improvement of nutrient absorption conditions as a result of ion homeostasis, sodium ion reduction and Artemisinin production conditions by rhizosphere B. cereus isolates E and B.
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Affiliation(s)
- Sara Salimian Rizi
- Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
| | - Zahra Rezayatmand
- Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
| | - Monireh Ranjbar
- Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
| | - Nasrin Yazdanpanahi
- Department of Biotechnology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
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Meinzer M, Ahmad N, Nielsen BL. Halophilic Plant-Associated Bacteria with Plant-Growth-Promoting Potential. Microorganisms 2023; 11:2910. [PMID: 38138054 PMCID: PMC10745547 DOI: 10.3390/microorganisms11122910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/18/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023] Open
Abstract
The salinization of soils is a growing agricultural concern worldwide. Irrigation practices, drought, and climate change are leading to elevated salinity levels in many regions, resulting in reduced crop yields. However, there is potential for a solution in the microbiome of halophytes, which are naturally salt-tolerant plants. These plants harbor a salt-tolerant microbiome in their rhizosphere (around roots) and endosphere (within plant tissue). These bacteria may play a significant role in conferring salt tolerance to the host plants. This leads to the possibility of transferring these beneficial bacteria, known as salt-tolerant plant-growth-promoting bacteria (ST-PGPB), to salt-sensitive plants, enabling them to grow in salt-affected areas to improve crop productivity. In this review, the background of salt-tolerant microbiomes is discussed and their potential use as ST-PGPB inocula is explored. We focus on two Gram-negative bacterial genera, Halomonas and Kushneria, which are commonly found in highly saline environments. These genera have been found to be associated with some halophytes, suggesting their potential for facilitating ST-PGPB activity. The study of salt-tolerant microbiomes and their use as PGPB holds promise for addressing the challenges posed by soil salinity in the context of efforts to improve crop growth in salt-affected areas.
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Affiliation(s)
- McKay Meinzer
- Department of Microbiology & Molecular Biology, Brigham Young University, Provo, UT 84602, USA;
| | - Niaz Ahmad
- National Institute for Biotechnology and Genetic Engineering College (NIBGE-C), Pakistan Institute for Engineering and Applied Sciences (PIEAS), Faisalabad 38000, Pakistan;
| | - Brent L. Nielsen
- National Institute for Biotechnology and Genetic Engineering College (NIBGE-C), Pakistan Institute for Engineering and Applied Sciences (PIEAS), Faisalabad 38000, Pakistan;
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Fry EL, Ashworth D, Allen KAJ, Chardon NI, Rixen C, Björkman MP, Björk RG, Stålhandske T, Molau M, Locke-King B, Cantillon I, McDonald C, Liu H, De Vries FT, Ostle NJ, Singh BK, Bardgett RD. Vegetation type, not the legacy of warming, modifies the response of microbial functional genes and greenhouse gas fluxes to drought in Oro-Arctic and alpine regions. FEMS Microbiol Ecol 2023; 99:fiad145. [PMID: 37951295 PMCID: PMC10673709 DOI: 10.1093/femsec/fiad145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/31/2023] [Accepted: 11/09/2023] [Indexed: 11/13/2023] Open
Abstract
Climate warming and summer droughts alter soil microbial activity, affecting greenhouse gas (GHG) emissions in Arctic and alpine regions. However, the long-term effects of warming, and implications for future microbial resilience, are poorly understood. Using one alpine and three Arctic soils subjected to in situ long-term experimental warming, we simulated drought in laboratory incubations to test how microbial functional-gene abundance affects fluxes in three GHGs: carbon dioxide, methane, and nitrous oxide. We found that responses of functional gene abundances to drought and warming are strongly associated with vegetation type and soil carbon. Our sites ranged from a wet, forb dominated, soil carbon-rich systems to a drier, soil carbon-poor alpine site. Resilience of functional gene abundances, and in turn methane and carbon dioxide fluxes, was lower in the wetter, carbon-rich systems. However, we did not detect an effect of drought or warming on nitrous oxide fluxes. All gene-GHG relationships were modified by vegetation type, with stronger effects being observed in wetter, forb-rich soils. These results suggest that impacts of warming and drought on GHG emissions are linked to a complex set of microbial gene abundances and may be habitat-specific.
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Affiliation(s)
- Ellen L Fry
- School of Earth and Environment Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
- Department of Biology, Edge Hill University, St Helens Road, Ormskirk, Lancashire, L39 4AP, United Kingdom
| | - Deborah Ashworth
- School of Earth and Environment Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Kimberley A J Allen
- School of Earth and Environment Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Nathalie Isabelle Chardon
- Biodiversity Research Centre, University of British Columbia, 2212 Main Mall Vancouver, BC V6T 1Z4, Canada
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, CH-7260 Davos Dorf, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Flüelastrasse 11, 7260 Davos Dorf, Switzerland
- Climate Change, Extremes and Natural Hazards in Alpine Regions Research Centre CERC, Flüelastrasse 11, 7260 Davos Dorf, Switzerland
| | - Mats P Björkman
- Department of Earth Sciences, University of Gothenburg, Box 100 405 30 Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Box 100 405 30 Gothenburg, Gothenburg, Sweden
| | - Robert G Björk
- Department of Earth Sciences, University of Gothenburg, Box 100 405 30 Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Box 100 405 30 Gothenburg, Gothenburg, Sweden
| | - Thomas Stålhandske
- Department of Earth Sciences, University of Gothenburg, Box 100 405 30 Gothenburg, Gothenburg, Sweden
| | - Mathias Molau
- Department of Earth Sciences, University of Gothenburg, Box 100 405 30 Gothenburg, Gothenburg, Sweden
| | - Brady Locke-King
- Department of Biology, Edge Hill University, St Helens Road, Ormskirk, Lancashire, L39 4AP, United Kingdom
| | - Isabelle Cantillon
- Department of Biology, Edge Hill University, St Helens Road, Ormskirk, Lancashire, L39 4AP, United Kingdom
| | - Catriona McDonald
- Hawkesbury Institute for the Environment, Western Sydney University, Bourke Street, Penrith, NSW, Australia
| | - Hongwei Liu
- Hawkesbury Institute for the Environment, Western Sydney University, Bourke Street, Penrith, NSW, Australia
| | - Franciska T De Vries
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, the Netherlands
| | - Nick J Ostle
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YW, United Kingdom
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, Western Sydney University, Bourke Street, Penrith, NSW, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Bourke Street, Penrith, NSW, Australia
| | - Richard D Bardgett
- School of Earth and Environment Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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Rodríguez-Valdecantos G, Torres-Rojas F, Muñoz-Echeverría S, del Rocío Mora-Ruiz M, Rosselló-Móra R, Cid-Cid L, Ledger T, González B. Aromatic compounds depurative and plant growth promotion rhizobacteria abilities of Allenrolfea vaginata ( Amaranthaceae) rhizosphere microbial communities from a solar saltern hypersaline soil. Front Microbiol 2023; 14:1251602. [PMID: 37954249 PMCID: PMC10635022 DOI: 10.3389/fmicb.2023.1251602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 10/09/2023] [Indexed: 11/14/2023] Open
Abstract
Introduction This work investigates whether rhizosphere microorganisms that colonize halophyte plants thriving in saline habitats can tolerate salinity and provide beneficial effects to their hosts, protecting them from environmental stresses, such as aromatic compound (AC) pollution. Methods To address this question, we conducted a series of experiments. First, we evaluated the effects of phenol, tyrosine, 4-hydroxybenzoic acid, and 2,4-dichlorophenoxyacetic (2,4-D) acids on the soil rhizosphere microbial community associated with the halophyte Allenrolfea vaginata. We then determined the ability of bacterial isolates from these microbial communities to utilize these ACs as carbon sources. Finally, we assessed their ability to promote plant growth under saline conditions. Results Our study revealed that each AC had a different impact on the structure and alpha and beta diversity of the halophyte bacterial (but not archaeal) communities. Notably, 2,4-D and phenol, to a lesser degree, had the most substantial decreasing effects. The removal of ACs by the rhizosphere community varied from 15% (2,4-D) to 100% (the other three ACs), depending on the concentration. Halomonas isolates were the most abundant and diverse strains capable of degrading the ACs, with strains of Marinobacter, Alkalihalobacillus, Thalassobacillus, Oceanobacillus, and the archaea Haladaptatus also exhibiting catabolic properties. Moreover, our study found that halophile strains Halomonas sp. LV-8T and Marinobacter sp. LV-48T enhanced the growth and protection of Arabidopsis thaliana plants by 30% to 55% under salt-stress conditions. Discussion These results suggest that moderate halophile microbial communities may protect halophytes from salinity and potential adverse effects of aromatic compounds through depurative processes.
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Affiliation(s)
- Gustavo Rodríguez-Valdecantos
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Felipe Torres-Rojas
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Sofía Muñoz-Echeverría
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Merit del Rocío Mora-Ruiz
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA UIB-CSIC), Esporles, Spain
| | - Ramon Rosselló-Móra
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA UIB-CSIC), Esporles, Spain
| | - Luis Cid-Cid
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Thomas Ledger
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Bernardo González
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
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Hamada MA, Soliman ERS. Characterization and genomics identification of key genes involved in denitrification-DNRA-nitrification pathway of plant growth-promoting rhizobacteria (Serratia marcescens OK482790). BMC Microbiol 2023; 23:210. [PMID: 37543572 PMCID: PMC10403818 DOI: 10.1186/s12866-023-02941-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/11/2023] [Indexed: 08/07/2023] Open
Abstract
BACKGROUND A wide variety of microorganisms, including bacteria, live in the rhizosphere zone of plants and have an impact on plant development both favorably and adversely. The beneficial outcome is due to the presence of rhizobacteria that promote plant growth (PGPR). RESULTS In this study, a bacterial strain was isolated from lupin rhizosphere and identified genetically as Serratia marcescens (OK482790). Several biochemically and genetically characteristics were confirmed in vitro and in vivo to determine the OK482790 strain ability to be PGPR. The in vitro results revealed production of different lytic enzymes (protease, lipase, cellulase, and catalase), antimicrobial compounds (hydrogen cyanide, and siderophores), ammonia, nitrite, and nitrate and its ability to reduce nitrate to nitrite. In silico and in vitro screening proposed possible denitrification-DNRA-nitrification pathway for OK482790 strain. The genome screening indicated the presence of nitrite and nitrate genes encoding Nar membrane bound sensor proteins (NarK, NarQ and NarX). Nitrate and nitrite reductase encoding genes (NarI, NarJ, NarH, NarG and NapC/NirT) and (NirB, NirC, and NirD) are also found in addition to nitroreductases (NTR) and several oxidoreductases. In vivo results on wheat seedlings confirmed that seedlings growth was significantly improved by soil inoculation of OK482790 strain. CONCLUSIONS This study provides evidence for participation of S. marcescens OK482790 in nitrogen cycling via the denitrification-DNRA-nitrification pathway and for its ability to produce several enzymes and compounds that support the beneficial role of plant-microbe interactions to sustain plant growth and development for a safer environment.
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Affiliation(s)
- Marwa A Hamada
- Botany and Microbiology Department, Faculty of Science, Helwan University, Helwan, Egypt
| | - Elham R S Soliman
- Botany and Microbiology Department, Faculty of Science, Helwan University, Helwan, Egypt.
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Li X, Zheng J, Wei W, Gong Z, Liu Z. The halophilic bacteria Gracilibacillus dipsosauri GDHT17 alleviates salt stress on perennial ryegrass seedlings. Front Microbiol 2023; 14:1213884. [PMID: 37564282 PMCID: PMC10411512 DOI: 10.3389/fmicb.2023.1213884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/12/2023] [Indexed: 08/12/2023] Open
Abstract
Introduction Adverse abiotic environmental conditions including excess salt in the soil, constantly challenge plants and disrupt the function of plants, even inflict damage on plants. Salt stress is one of the major limiting factors for agricultural productivity and severe restrictions on plant growth. One of the critical ways to improve plant salt tolerance is halotolerant bacteria application. However, few such halotolerant bacteria were known and should be explored furtherly. Methods Halophilic bacterium strain was isolated from saline soil with serial dilution and identified with classical bacteriological tests and 16S rRNA analysis. Perennial ryegrass (Lolium perenne L) was used in this study to evaluate the potential effect of the bacteria. Results and discussion A halophilic bacterium strain GDHT17, was isolated from saline soil, which grows in the salinities media with 1.0%, 5.0%, and 10.0% (w/v) NaCl, and identified as Gracilibacillus dipsosauri. Inoculating GDHT17 can significantly promote ryegrass's seedling height and stem diameter and increase the root length, diameter, and surface area at different salt concentrations, indicating the significant salt stress alleviating effect of GDHT17 on the growth of ryegrass. The alleviating effect on roots growth showed more effective, especially on the root length, which increased significantly by 26.39%, 42.59%, and 98.73% at salt stress of 100 mM, 200 mM, and 300 mM NaCl when the seedlings were inoculated with GDHT17. Inoculating GDHT17 also increases perennial ryegrass biomass, water content, chlorophyll and carotenoid content under salt stress. The contents of proline and malonaldehyde in the seedlings inoculated with GDHT17 increased by 83.50% and 6.87%, when treated with 300 mM NaCl; however, the contents of MDA and Pro did not show an apparent effect under salt stress of 100 mM or 200 mM NaCl. GDHT17-inoculating maintained the Na+/K+ ratio in the salt-stressed ryegrass. The Na+/K+ ratio decreased by 26.52%, 6.89%, and 29.92% in the GDHT17-inoculated seedling roots treated with 100 mM, 200 mM, and 300 mM NaCl, respectively. The GDHT17-inoculating increased the POD and SOD activity of ryegrass seedlings by 25.83% and 250.79%, respectively, at a salt stress of 300 mM NaCl, indicating the properties of GDHT17, improving the activity of antioxidant enzymes of ryegrass at the salt-stress condition. Our results suggest that G. dipsosauri GDHT17 may alleviate salt stress on ryegrass in multiple ways; hence it can be processed into microbial inoculants to increase salt tolerance of ryegrass, as well as other plants in saline soil.
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Affiliation(s)
| | | | | | | | - Zhenyu Liu
- College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong, China
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Flores Clavo R, Valladolid-Suyón E, Reinoza-Farroñan K, Asmat Ortega C, Riboldi Monteiro PH, Apaza-Castillo GA, Zuñiga-Valdera G, Fantinatti Garboggini F, Iglesias-Osores S, Carreño-Farfán CR. Rhizobacterial Isolates from Prosopis limensis Promote the Growth of Raphanus sativus L. Under Salt Stress. Curr Microbiol 2023; 80:269. [PMID: 37402857 DOI: 10.1007/s00284-023-03379-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 06/14/2023] [Indexed: 07/06/2023]
Abstract
Microbial biotechnology employes techniques that rely based on the natural interactions that occur in ecosystems. Bacteria, including rhizobacteria, play an important role in plant growth, providing agricultural crops with an alternative that can mitigate the negative effects of abiotic stress, such as those caused by saline environments. In this study, bacterial isolates were obtained from soil and roots of Prosopis limensis Bentham from the department of Lambayeque, Peru. This region has high salinity levels, therefore, the collected samples were used to isolate plant growth-promoting rhizobacteria (PGPR), which were identified through morphological, and physical-biochemical characteristics. These salt tolerant bacteria were screened phosphate solubilization, indole acetic acid, deaminase activity and molecular characterization by 16S rDNA sequencing. Eighteen samples from saline soils of the Prosopis limensis plants in the northern coastal desert of San Jose district, Lambayeque, Peru. The bacterial isolates were screened for salt tolerance ranging from 2 to 10%, a total of 78 isolates were found. Isolates 03, 13 and 31 showed maximum salt tolerance at 10%, in vitro ACC production, phosphate solubilization and IAA production. The three isolates were identified by sequencing the amplified 16S rRNA gene and were found to be Pseudomonas sp. 03 (MW604823), Pseudomonas sp. 13 (MW604824) and Bordetella sp. 31 (MW604826). These microorganisms promoted the germination of radish plants and increased the germination rates for treatments T2, T3 and T4 by 129, 124 and 118% respectively. The beneficial effects of salt tolerant PGPR isolates isolated from saline environments can be new species, used to overcome the detrimental effects of salt stress on plants. The biochemical response and inoculation of the three isolates prove the potential of using these strains as a source of products that can be employed for the development of new compounds proving their potential as biofertilizers for saline environments.
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Affiliation(s)
- Rene Flores Clavo
- Cesar Vallejo University, Lambayeque, Perú.
- Department of Biotechnology, Center for Research and Innovation in Multidisciplinary Active Sciences (CIICAM), Pasaje Real Street No 174, Chiclayo, Lambayeque, Perú.
- Division of Microbial Resources of Chemical, Biological and Agricultural Pluridisciplinary Research Center (CPQBA), University of Campinas (UNICAMP), Alexandre Cazellato No 999, Campinas, Paulínia, São Paulo, Brazil.
| | - Esteban Valladolid-Suyón
- Microbial Biotechnology Research Laboratory, Department of Microbiology and Parasitology, Pedro Ruiz Gallo National University, Juan XXIII No 391 Street, Chiclayo, Lambayeque, Peru
| | - Karin Reinoza-Farroñan
- Microbial Biotechnology Research Laboratory, Department of Microbiology and Parasitology, Pedro Ruiz Gallo National University, Juan XXIII No 391 Street, Chiclayo, Lambayeque, Peru
| | | | - Pedro Henrique Riboldi Monteiro
- Department of Biotechnology, Center for Research and Innovation in Multidisciplinary Active Sciences (CIICAM), Pasaje Real Street No 174, Chiclayo, Lambayeque, Perú
- Division of Microbial Resources of Chemical, Biological and Agricultural Pluridisciplinary Research Center (CPQBA), University of Campinas (UNICAMP), Alexandre Cazellato No 999, Campinas, Paulínia, São Paulo, Brazil
| | - Gladys A Apaza-Castillo
- Department of Biotechnology, Center for Research and Innovation in Multidisciplinary Active Sciences (CIICAM), Pasaje Real Street No 174, Chiclayo, Lambayeque, Perú
- Department of Genetics, "Luiz de Queiroz" College of Agriculture, University of São Paulo (USP), Piracicaba, São Paulo, Brazil
| | - Gabriel Zuñiga-Valdera
- Microbial Biotechnology Research Laboratory, Department of Microbiology and Parasitology, Pedro Ruiz Gallo National University, Juan XXIII No 391 Street, Chiclayo, Lambayeque, Peru
| | - Fabiana Fantinatti Garboggini
- Division of Microbial Resources of Chemical, Biological and Agricultural Pluridisciplinary Research Center (CPQBA), University of Campinas (UNICAMP), Alexandre Cazellato No 999, Campinas, Paulínia, São Paulo, Brazil
| | - Sebastian Iglesias-Osores
- Microbial Biotechnology Research Laboratory, Department of Microbiology and Parasitology, Pedro Ruiz Gallo National University, Juan XXIII No 391 Street, Chiclayo, Lambayeque, Peru
| | - Carmen Rosa Carreño-Farfán
- Microbial Biotechnology Research Laboratory, Department of Microbiology and Parasitology, Pedro Ruiz Gallo National University, Juan XXIII No 391 Street, Chiclayo, Lambayeque, Peru
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11
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Li Z, Chi Y, Su X, Ye Z, Ren X. Rhizobium Soaking Promoted Maize Growth by Altering Rhizosphere Microbiomes and Associated Functional Genes. Microorganisms 2023; 11:1654. [PMID: 37512827 PMCID: PMC10383385 DOI: 10.3390/microorganisms11071654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Rhizobium is a Gram-negative bacterium, which dissolves minerals, produces growth hormones, promotes root growth, and protects plants from different soil-borne pathogens. In the present study, roots, stalks, and fresh weight of maize (Zea mays L.) were significantly increased after soaking in Bradyrhizobium japonicum compared with the control. Subsequently, transcriptome sequencing results of the whole maize plant soaked in B. japonicum showed that multiple growth and development-related genes were up-regulated more than 100-fold compared to the control. Furthermore, the abundance of plant growth promoting bacteria, such as Acidobacteria Subgroup_6 and Chloroflexi KD4-96, were increased significantly. On the contrary, the abundance of multiple pathogens, such as Curvularia, Fusarium and Mycocentrospora, were significantly decreased. Moreover, inoculation with B. japonicum could inhibit the infection of the pathogen Fusarium graminearum in maize. These results suggest that soaking seeds in B. japonicum may affect the expression of maize growth and development-related genes as the bacteria changes the soil microorganism community structure. These findings may help to expand the application of B. japonicum in crop production and provide new opportunities for food security.
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Affiliation(s)
- Zhao Li
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230001, China
| | - Yu Chi
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230001, China
| | - Xianyan Su
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230001, China
| | - Zhenghe Ye
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230001, China
| | - Xuexiang Ren
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230001, China
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12
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Jalal A, Oliveira CEDS, Rosa PAL, Galindo FS, Teixeira Filho MCM. Beneficial Microorganisms Improve Agricultural Sustainability under Climatic Extremes. Life (Basel) 2023; 13:life13051102. [PMID: 37240747 DOI: 10.3390/life13051102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/08/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
The challenging alterations in climate in the last decades have had direct and indirect influences on biotic and abiotic stresses that have led to devastating implications on agricultural crop production and food security. Extreme environmental conditions, such as abiotic stresses, offer great opportunities to study the influence of different microorganisms in plant development and agricultural productivity. The focus of this review is to highlight the mechanisms of plant growth-promoting microorganisms (especially bacteria and fungi) adapted to environmental induced stresses such as drought, salinity, heavy metals, flooding, extreme temperatures, and intense light. The present state of knowledge focuses on the potential, prospective, and biotechnological approaches of plant growth-promoting bacteria and fungi to improve plant nutrition, physio-biochemical attributes, and the fitness of plants under environmental stresses. The current review focuses on the importance of the microbial community in improving sustainable crop production under changing climatic scenarios.
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Affiliation(s)
- Arshad Jalal
- Department of Plant Health, Rural Engineering and Soils, Faculty of Engineering, São Paulo State University (UNESP), Av. Brasil 56-Centro, Ilha Solteira 15385-000, SP, Brazil
| | - Carlos Eduardo da Silva Oliveira
- Department of Plant Health, Rural Engineering and Soils, Faculty of Engineering, São Paulo State University (UNESP), Av. Brasil 56-Centro, Ilha Solteira 15385-000, SP, Brazil
| | - Poliana Aparecida Leonel Rosa
- Department of Plant Health, Rural Engineering and Soils, Faculty of Engineering, São Paulo State University (UNESP), Av. Brasil 56-Centro, Ilha Solteira 15385-000, SP, Brazil
| | - Fernando Shintate Galindo
- Faculty of Agricultural Sciences and Technology, São Paulo State University (UNESP), Campus of Dracena, Sao Paulo 17900-000, SP, Brazil
| | - Marcelo Carvalho Minhoto Teixeira Filho
- Department of Plant Health, Rural Engineering and Soils, Faculty of Engineering, São Paulo State University (UNESP), Av. Brasil 56-Centro, Ilha Solteira 15385-000, SP, Brazil
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13
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Ghazala I, Chiab N, Saidi MN, Gargouri-Bouzid R. The Plant Growth-Promoting Bacteria Strain Bacillus mojavensis I4 Enhanced Salt Stress Tolerance in Durum Wheat. Curr Microbiol 2023; 80:178. [PMID: 37036517 DOI: 10.1007/s00284-023-03288-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/25/2023] [Indexed: 04/11/2023]
Abstract
Plant growth and production are adversely affected by soil salinity. A plant growth-promoting bacteria (PGPB) designated as the "I4 strain" of Bacillus mojavensis was isolated from Tunisian soil (Sfax, Tunisia) and showed the ability to be grown in the presence of NaCl concentrations ranging from 0 to 10% in Luria Bertani (LB) medium. The PGPB-mediated salt tolerance in durum wheat was evaluated. The physiological parameters such as growth, shoot and root length, dry and fresh weight were higher in I4-inoculated wheat plants in comparison with non-treated plants under salt stress. Results showed that this strain promoted wheat growth and preserved the membrane damage by notably lowering the electrolytes leakage and malondialdehyde content in contrast to non-inoculated plants. Moreover, leaf chlorophyll content, biochemical parameters and antioxidant enzyme activities measurement showed a better salt and heavy metal stress adaptation of the I4-inoculated plants. Due to these outcomes, it could be suggested that the inoculation of the PGPB I4 strain enhanced the wheat plant's growth, especially under salt stress conditions. This study confirms the ameliorative role played by PGPB in tolerating salt stress in wheat and their potential use as biofertilizers to enhance its growth in saline soil and help in promoting this plant's culture to provide food security under these perturbed global circumstances.
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Affiliation(s)
- Imen Ghazala
- Laboratory of Plant Improvement and Valorization of Agricultural Resources, National Engineering School of Sfax, Sfax, Tunisia.
| | - Nour Chiab
- Laboratory of Plant Improvement and Valorization of Agricultural Resources, National Engineering School of Sfax, Sfax, Tunisia
| | - Mohamed Najib Saidi
- Biotechnology and Plant Improvement Laboratory, Biotechnology Center of Sfax, Sfax, Tunisia
| | - Radhia Gargouri-Bouzid
- Laboratory of Plant Improvement and Valorization of Agricultural Resources, National Engineering School of Sfax, Sfax, Tunisia
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14
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Dragojević M, Stankovic N, Djokic L, Raičević V, Jovičić-Petrović J. Endorhizosphere of indigenous succulent halophytes: a valuable resource of plant growth promoting bacteria. ENVIRONMENTAL MICROBIOME 2023; 18:20. [PMID: 36934265 PMCID: PMC10024849 DOI: 10.1186/s40793-023-00477-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
The adaptability of halophytes to increased soil salinity is related to complex rhizosphere interactions. In this study, an integrative approach, combining culture-independent and culture-dependent techniques was used to analyze the bacterial communities in the endorizosphere of indigenous succulent halophytes Salicornia europaea, Suaeda maritima, and Camphorosma annua from the natural salt marshes of Slano Kopovo (Serbia). The 16 S rDNA analyses gave, for the first time, an insight into the composition of the endophytic bacterial communities of S. maritima and C. annua. We have found that the composition of endophyte microbiomes in the same habitat is to some extent influenced by plant species. A cultivable portion of the halophyte microbiota was tested at different NaCl concentrations for the set of plant growth promoting (PGP) traits. Through the mining of indigenous halotolerant endophytes, we obtained a collection representing a core endophyte microbiome conferring desirable PGP traits. The majority (65%) of the selected strains belonged to the common halotolerant/halophilic genera Halomonas, Kushneria, and Halobacillus, with representatives exhibiting multiple PGP traits, and retaining beneficial traits in conditions of the increased salinity. The results suggest that the root endosphere of halophytes is a valuable source of PGP bacteria supporting plant growth and fitness in salt-affected soils.
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Affiliation(s)
- Milica Dragojević
- Faculty of Agriculture, University of Belgrade, Nemanjina 6, Zemun, 11080 Serbia
| | - Nada Stankovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, Serbia
| | - Lidija Djokic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, Serbia
| | - Vera Raičević
- Faculty of Agriculture, University of Belgrade, Nemanjina 6, Zemun, 11080 Serbia
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15
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Shahid M, Singh UB, Khan MS, Singh P, Kumar R, Singh RN, Kumar A, Singh HV. Bacterial ACC deaminase: Insights into enzymology, biochemistry, genetics, and potential role in amelioration of environmental stress in crop plants. Front Microbiol 2023; 14:1132770. [PMID: 37180266 PMCID: PMC10174264 DOI: 10.3389/fmicb.2023.1132770] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/20/2023] [Indexed: 05/16/2023] Open
Abstract
Growth and productivity of crop plants worldwide are often adversely affected by anthropogenic and natural stresses. Both biotic and abiotic stresses may impact future food security and sustainability; global climate change will only exacerbate the threat. Nearly all stresses induce ethylene production in plants, which is detrimental to their growth and survival when present at higher concentrations. Consequently, management of ethylene production in plants is becoming an attractive option for countering the stress hormone and its effect on crop yield and productivity. In plants, ACC (1-aminocyclopropane-1-carboxylate) serves as a precursor for ethylene production. Soil microorganisms and root-associated plant growth promoting rhizobacteria (PGPR) that possess ACC deaminase activity regulate growth and development of plants under harsh environmental conditions by limiting ethylene levels in plants; this enzyme is, therefore, often designated as a "stress modulator." TheACC deaminase enzyme, encoded by the AcdS gene, is tightly controlled and regulated depending upon environmental conditions. Gene regulatory components of AcdS are made up of the LRP protein-coding regulatory gene and other regulatory components that are activated via distinct mechanisms under aerobic and anaerobic conditions. ACC deaminase-positive PGPR strains can intensively promote growth and development of crops being cultivated under abiotic stresses including salt stress, water deficit, waterlogging, temperature extremes, and presence of heavy metals, pesticides and other organic contaminants. Strategies for combating environmental stresses in plants, and improving growth by introducing the acdS gene into crop plants via bacteria, have been investigated. In the recent past, some rapid methods and cutting-edge technologies based on molecular biotechnology and omics approaches involving proteomics, transcriptomics, metagenomics, and next generation sequencing (NGS) have been proposed to reveal the variety and potential of ACC deaminase-producing PGPR that thrive under external stresses. Multiple stress-tolerant ACC deaminase-producing PGPR strains have demonstrated great promise in providing plant resistance/tolerance to various stressors and, therefore, it could be advantageous over other soil/plant microbiome that can flourish under stressed environments.
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Affiliation(s)
- Mohammad Shahid
- Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, Uttar Pradesh, India
- *Correspondence: Mohammad Shahid, ; Udai B. Singh, ; Prakash Singh,
| | - Udai B. Singh
- Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, Uttar Pradesh, India
- *Correspondence: Mohammad Shahid, ; Udai B. Singh, ; Prakash Singh,
| | - Mohammad Saghir Khan
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
| | - Prakash Singh
- Department of Plant Breeding and Genetics, Veer Kunwar Singh College of Agriculture, Bihar Agricultural University, Dumraon, India
- *Correspondence: Mohammad Shahid, ; Udai B. Singh, ; Prakash Singh,
| | - Ratan Kumar
- Krishi Vigyan Kendra, Rohtas, Bihar Agricultural University, Bikramganj, Bihar, India
| | - Raj Narian Singh
- Directorate of Extension Education, Bihar Agricultural University, Bhagalpur, Bihar, India
| | - Arun Kumar
- Swamy Keshwanand Rajasthan Agriculture University, Bikaner, Rajasthan, India
| | - Harsh V. Singh
- Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, Uttar Pradesh, India
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16
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Gupta A, Rai S, Bano A, Sharma S, Kumar M, Binsuwaidan R, Suhail Khan M, Upadhyay TK, Alshammari N, Saeed M, Pathak N. ACC Deaminase Produced by PGPR Mitigates the Adverse Effect of Osmotic and Salinity Stresses in Pisum sativum through Modulating the Antioxidants Activities. PLANTS (BASEL, SWITZERLAND) 2022; 11:3419. [PMID: 36559529 PMCID: PMC9782781 DOI: 10.3390/plants11243419] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Salinity-induced ethylene production and reactive oxygen species (ROS) inhibit agricultural productivity. The plant synthesizes ethylene directly from aminocyclopropane-1-carboxylic acid (ACC). By using ACC as a nitrogen source, bacteria with ACC deaminase (ACCD) inhibit the overproduction of ethylene, thereby maintaining the ROS. The present study investigated the ACCD activity of previously identified rhizobacterial strains in Dworkin and Foster (DF) minimal salt media supplemented with 5 mM ACC (as N-source). Bacterial isolates GKP KS2_7 (Pseudomonas aeruginosa) and MBD 133 (Bacillus subtilis) could degrade ACC into α-ketobutyrate, exhibiting ACCD activity producing more than ~257 nmol of α-ketobutyrate mg protein−1 h−1, and were evaluated for other plant growth-promoting (PGP) traits including indole acetic acid production (>63 µg/mL), phosphate solubilization (>86 µg mL−1), siderophore (>20%) ammonia and exopolysaccharide production. Furthermore, Fourier Transform Infrared analysis also demonstrated α-ketobutyrate liberation from ACC deamination in DF minimal salt media, thereby confirming the ACCD activity. These isolates also showed enhanced tolerance to salinity stress of 3% w/v NaCl in vitro, in addition to facilitating multifarious PGP activities. Seed bacterization by these ACCD-producing bacterial isolates (GKP KS2_7 and MBD 133) revealed a significant decline in stress-stimulated ethylene levels and its associated growth inhibition during seedling germination. They also mitigated the negative effects of salt stress and increased the root-shoot length, fresh and dry weight of root and shoot, root-shoot biomass, total sugar, protein, reducing sugar, chlorophyll content, and antioxidants enzymes in Pisum sativum. As a result, these strains (GKP KS2_7 and MBD 133) might be applied as biofertilizers to counteract the negative effects of soil salinity.
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Affiliation(s)
- Anmol Gupta
- IIRC-3, Plant-Microbe Interaction and Molecular Immunology Laboratory, Department of Biosciences, Faculty of Science, Integral University, Lucknow 226026, India
| | - Smita Rai
- IIRC-3, Plant-Microbe Interaction and Molecular Immunology Laboratory, Department of Biosciences, Faculty of Science, Integral University, Lucknow 226026, India
| | - Ambreen Bano
- IIRC-3, Plant-Microbe Interaction and Molecular Immunology Laboratory, Department of Biosciences, Faculty of Science, Integral University, Lucknow 226026, India
| | - Swati Sharma
- IIRC-3, Plant-Microbe Interaction and Molecular Immunology Laboratory, Department of Biosciences, Faculty of Science, Integral University, Lucknow 226026, India
| | - Manoj Kumar
- CSIR—National Botanical Research Institute, Rana Pratap Marg, Lucknow 226001, India
| | - Reem Binsuwaidan
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia
| | - Mohammad Suhail Khan
- Department of Public Health, College of Applied Medical Sciences, Khamis Mushait Campus, King Khalid University, Abha 62521, Saudi Arabia
| | - Tarun Kumar Upadhyay
- Department of Biotechnology, Parul Institute of Applied Sciences and Centre for Research for Development, Parul University, Vadodara 391760, India
| | - Nawaf Alshammari
- Department of Biology, College of Sciences, University of Hail, Hail 55476, Saudi Arabia
| | - Mohd Saeed
- Department of Biology, College of Sciences, University of Hail, Hail 55476, Saudi Arabia
| | - Neelam Pathak
- Department of Biochemistry, Dr. Ram Manohar Lohia Avadh University, Ayodhya 224001, India
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17
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Li Y, Zhou M, Li C, Pan X, Lv N, Ye Z, Zhu G, Zhao Q, Cai G. Inoculating indoleacetic acid bacteria promotes the enrichment of halotolerant bacteria during secondary fermentation of composting. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 322:116021. [PMID: 36067675 DOI: 10.1016/j.jenvman.2022.116021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
The secondary fermentation stage is critical for stabilizing composting products and producing various secondary metabolites. However, the low metabolic rate of mesophilic bacteria is regarded as the rate-limiting stage in composting process. In present study, two indoleacetic acid (IAA)-producing bacteria (Bacillus safensis 33C and Corynebacterium stationis subsp. safensis 29B) were inoculated to strengthen the secondary fermentation stage to improve the plant-growth promoting potential of composting products. The results showed that the addition of IAA-producing bacteria promoted the assimilation of soluble salt, the condensation and aromatization of humus, and the accumulation of dissolved organic nitrogen (DON) and dissolved organic carbon (DOC). The bioaugmentation strategy also enabled faster microbial community succession during the medium-late phase of secondary fermentation. However, the colonization of Bacillus and Corynebacterium could not explain the disproportionate increase of IAA yield, which reached up to 5.6 times compared to the control group. Deeper analysis combined with physicochemical properties and microbial community structure suggested that IAA-producing bacteria might induce the increase of salinity, which enriched halotolerant bacteria capable of producing IAA, such as Halomonas, Brachybacterium and Flavobacterium. In addition, the results also proved that it was necessary to shorten secondary fermentation time to avoid IAA degradation without affecting composting maturity. In summary, enhancing secondary fermentation of composting via adding proper IAA-producing bacteria is an efficient strategy for upgrading the quality of organic fertilizer.
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Affiliation(s)
- Yanlin Li
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mingdian Zhou
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chunxing Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaofang Pan
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Nan Lv
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Zhilong Ye
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Gefu Zhu
- School of Environment and Nature Resources, Renmin University of China, Beijing, 100872, China; Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture and Rural Affairs, China.
| | - Quanbao Zhao
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
| | - Guanjing Cai
- Biology Department and Institute of Marine Sciences, College of Science, And Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, China.
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18
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Stegelmeier AA, Rose DM, Joris BR, Glick BR. The Use of PGPB to Promote Plant Hydroponic Growth. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11202783. [PMID: 36297807 PMCID: PMC9611108 DOI: 10.3390/plants11202783] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/11/2022] [Accepted: 10/18/2022] [Indexed: 05/13/2023]
Abstract
Improvements to the world's food supply chain are needed to ensure sufficient food is produced to meet increasing population demands. Growing food in soilless hydroponic systems constitutes a promising strategy, as this method utilizes significantly less water than conventional agriculture, can be situated in urban areas, and can be stacked vertically to increase yields per acre. However, further research is needed to optimize crop yields in these systems. One method to increase hydroponic plant yields involves adding plant growth-promoting bacteria (PGPB) into these systems. PGPB are organisms that can significantly increase crop yields via a wide range of mechanisms, including stress reduction, increases in nutrient uptake, plant hormone modulation, and biocontrol. The aim of this review is to provide critical information for researchers on the current state of the use of PGPB in hydroponics so that meaningful advances can be made. An overview of the history and types of hydroponic systems is provided, followed by an overview of known PGPB mechanisms. Finally, examples of PGPB research that has been conducted in hydroponic systems are described. Amalgamating the current state of knowledge should ensure that future experiments can be designed to effectively transition results from the lab to the farm/producer, and the consumer.
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Affiliation(s)
- Ashley A. Stegelmeier
- Ceragen Inc., 151 Charles St W, Suite 199, Kitchener, ON N2G 1H6, Canada
- Correspondence: author:
| | - Danielle M. Rose
- Ceragen Inc., 151 Charles St W, Suite 199, Kitchener, ON N2G 1H6, Canada
| | - Benjamin R. Joris
- Ceragen Inc., 151 Charles St W, Suite 199, Kitchener, ON N2G 1H6, Canada
| | - Bernard R. Glick
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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19
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Mahdi I, Allaoui A, Fahsi N, Biskri L. Bacillus velezensis QA2 Potentially Induced Salt Stress Tolerance and Enhanced Phosphate Uptake in Quinoa Plants. Microorganisms 2022; 10:microorganisms10091836. [PMID: 36144437 PMCID: PMC9505587 DOI: 10.3390/microorganisms10091836] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Plant Growth-Promoting Rhizobacteria (PGPR) have attracted much attention in agriculture biotechnology as biological inputs to sustain crop production. The present study describes a halotolerant phosphate solubilizing bacterium associated with quinoa plant roots. Based on a metabolic screening, one bacterial isolate, named QA2, was selected and screened for PGPR traits. This isolate solubilized both inorganic phosphate and zinc, produced indole-3-acetic acid, ammonia, hydrogen cyanide, cellulase, and (to be deleted) protease, and induced biofilm formation. We demonstrated that QA2 exhibited both antimicrobial and ion metabolism activities and tolerated high salt concentration at up to 11% NaCl. Genotyping analyses, using 16S rRNA and chaperonin cpn60 genes, revealed that QA2 belongs to the species of Bacillus velezensis. Using the quinoa model cultivated under a saline condition, we demonstrated that QA2 promoted plant growth and mitigated the saline irrigation effects. Analysis of harvested plants revealed that QA2 induced a significant increase of both leaf chlorophyll index by 120.86% (p < 0.05) and P uptake by 41.17% (p < 0.05), while the content of Na+ was drastically decreased. Lastly, a bibliometric data analysis highlighted the panoramic view of studies carried out so far on B. velezensis strains. Our investigation presents a holistic view of the potential application of B. velezensis as a biological inoculant to promote plant growth, control pathogen attacks, and mitigate the salinity effect of quinoa plants. Further investigations are still needed to demonstrate these effects in field conditions.
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Affiliation(s)
- Ismail Mahdi
- Microbiology Laboratory, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir 43150, Morocco
| | - Abdelmounaaim Allaoui
- Microbiology Laboratory, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir 43150, Morocco
| | - Nidal Fahsi
- Microbiology Laboratory, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir 43150, Morocco
| | - Latefa Biskri
- Microbiology Laboratory, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir 43150, Morocco
- African Genome Center (AGC), Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir 43150, Morocco
- Correspondence: ; Tel.: +212-52502926
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Shahid M, Al-Khattaf FS, Danish M, Zeyad MT, Atef Hatamleh A, Mohamed A, Ali S. PGPR Kosakonia Radicincitans KR-17 Increases the Salt Tolerance of Radish by Regulating Ion-Homeostasis, Photosynthetic Molecules, Redox Potential, and Stressor Metabolites. FRONTIERS IN PLANT SCIENCE 2022; 13:919696. [PMID: 35979076 PMCID: PMC9376370 DOI: 10.3389/fpls.2022.919696] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/10/2022] [Indexed: 05/10/2023]
Abstract
Among abiotic stresses, salinity is a significant limiting factor affecting agricultural productivity, survival, and production, resulting in significant economic losses. Considering the salinity problem, the goal of this study was to identify a halotolerant beneficial soil bacterium to circumvent salinity-induced phytotoxicity. Here, strain KR-17 (having an irregular margin; a mucoid colony; Gm-ve short rod; optimum temperature, 30°C; pH 7.0; no any pigmentation; showed a positive response to citrate utilization, catalase, starch, sucrose, lactose, and dextrose, etc.) recovered from rhizosphere soils of the potato-cultivating field, tolerated surprisingly a high (18% NaCl; 3.-M concentration) level of salt and identified as Kosakonia radicincitans (Accession No. OM348535). This strain was discovered to be metabolically active, synthesized essential PGP bioactive molecules like indole-3-acetic acid (IAA), siderophore (iron-chelating compounds), ACC deaminase, and ammonia, the quantity of which, however, increased with increasing NaCl concentrations. Here, Raphanus sativus L. (radish) was taken as a model crop to evaluate the adverse impact of NaCl, as well as salinity alleviation by halotolerant K. radicincitans. Salinity-induced toxicity to R. sativus was increased in a dose-dependent way, as observed both in vitro and in vivo conditions. Maximum NaCl levels (15%) demonstrated more extreme harm and considerably reduced the plant's biological features. However, membrane damage, relative leaf water content (RLWC), stressor metabolites, and antioxidant enzymes were increased as NaCl concentration increased. In contrast, halotolerant K. radicincitans KR-17 relieved salinity stress and enhanced the overall performance of R. sativus (L.) by increasing germination efficiency, dry biomass, and leaf pigments even in salt-challenged conditions. Additionally, KR-17 inoculation significantly (p ≤ 0.05) improved plant mineral nutrients (Na, K, Ca, Mg, Zn, Fe, Cu, P, and N). Following inoculation, strain KR-17 enhanced the protein, carbohydrates, root pigments, amino acids (AsA and Lys), lipids, and root alkaloids in R. sativus (L.). Besides these, due to PGPR seed priming in NaCl-stressed/non-stressed conditions, membrane damage, RLWC, stressor metabolites, and antioxidant defense enzymes were dramatically reduced. The strong biofilm-forming capacity of K. radicincitans could result in both in vitro and in vivo colonization under NaCl stress. Conclusively, halotolerant K. radicincitans KR-17 may probably be investigated affordably as the greatest way to increase the production of radish under salinity-stressed soils.
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Affiliation(s)
- Mohammad Shahid
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, India
| | - Fatimah S. Al-Khattaf
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad Danish
- Section of Plant Pathology and Nematology, Department of Botany, Aligarh Muslim University, Aligarh, India
| | | | - Ashraf Atef Hatamleh
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | | | - Sajad Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan, South Korea
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Fadiji AE, Santoyo G, Yadav AN, Babalola OO. Efforts towards overcoming drought stress in crops: Revisiting the mechanisms employed by plant growth-promoting bacteria. Front Microbiol 2022; 13:962427. [PMID: 35966701 PMCID: PMC9372271 DOI: 10.3389/fmicb.2022.962427] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Globally, agriculture is under a lot of pressure due to rising population and corresponding increases in food demand. However, several variables, including improper mechanization, limited arable land, and the presence of several biotic and abiotic pressures, continually impact agricultural productivity. Drought is a notable destructive abiotic stress and may be the most serious challenge confronting sustainable agriculture, resulting in a significant crop output deficiency. Numerous morphological and physiological changes occur in plants as a result of drought stress. Hence, there is a need to create mitigation techniques since these changes might permanently harm the plant. Current methods used to reduce the effects of drought stress include the use of film farming, super-absorbent hydrogels, nanoparticles, biochar, and drought-resistant plant cultivars. However, most of these activities are money and labor-intensive, which offer limited plant improvement. The use of plant-growth-promoting bacteria (PGPB) has proven to be a preferred method that offers several indirect and direct advantages in drought mitigation. PGPB are critical biological elements which have favorable impacts on plants’ biochemical and physiological features, leading to improved sugar production, relative water content, leaf number, ascorbic acid levels, and photosynthetic pigment quantities. This present review revisited the impacts of PGPB in ameliorating the detrimental effects of drought stress on plants, explored the mechanism of action employed, as well as the major challenges encountered in their application for plant growth and development.
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Affiliation(s)
- Ayomide Emmanuel Fadiji
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
| | - Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
| | - Ajar Nath Yadav
- Microbial Biotechnology Laboratory, Department of Biotechnology, Eternal University, Baru Sahib, India
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
- *Correspondence: Olubukola Oluranti Babalola,
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Zakavi M, Askari H, Shahrooei M. Maize growth response to different Bacillus strains isolated from a salt-marshland area under salinity stress. BMC PLANT BIOLOGY 2022; 22:367. [PMID: 35879654 PMCID: PMC9317119 DOI: 10.1186/s12870-022-03702-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Maize (Zea mays) growth performance has been hindered due to the high soil salinity. Salinity is one of the most severe abiotic stresses that has led to growth imbalance and profitability of harvests in arid and semi-arid regions. Plants have taken advantage of salt-tolerant bacteria as plant growth-promoters to enhance growth and reduce the adverse effects of salinity through the regulation of some biochemical, physiological, and molecular features. Preferences for non-chemical, eco-friendly, and economical approaches have caused the inquiry of the Bacillus genus as a joint group of plant growth-promoting rhizobacteria known to alleviate salt-stress impacts. In the present study, halotolerant Bacillus strains were isolated from salt-marshland soil and characterized for their physiological, molecular, and biochemical properties. Twenty-four bacterial isolates collected from high saline fields of salt marshland were analyzed by MALDI-TOF MS proteome analysis, which confirmed the taxonomic affiliation with Bacillus cereus, Bacillus subtilis, Bacillus atrophaeus, and Bacillus thorngiensis. Applying the isolates on maize plants as bio-inoculant bacteria obviously increased the growth parameters (P < 0.01). Pot experiments showed that isolates 74 and 90 were the most prominent strains to minimize the harmful effects of salinity. Its effects are heightening the potassium/sodium ratio and K-Na selectivity in shoots and roots measured by flame atomic absorption photometry (AAS). Accordingly, Bacillus cereus isolate 74 showed a maximum increase in dry weights of the shoot (133.89%), root (237.08%), length of the shoot (125%), and root (119.44%) compared to the control condition. Our findings suggest that bacteria isolated from marshland may be an economical and simple means to increase plant growth and resistance to high salinity soil conditions.
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Affiliation(s)
- Maryam Zakavi
- Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Hossein Askari
- Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Mohammad Shahrooei
- Department of Microbiology and Immunology, Clinical and Diagnostic Immunology, KU Leuven, Leuven, Belgium
- Medical Laboratory of Dr. Shahrooei, Tehran, Iran
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Yue Z, Chen Y, Wang Y, Zheng L, Zhang Q, Liu Y, Hu C, Chen C, Ma K, Sun Z. Halotolerant Bacillus altitudinis WR10 improves salt tolerance in wheat via a multi-level mechanism. FRONTIERS IN PLANT SCIENCE 2022; 13:941388. [PMID: 35909740 PMCID: PMC9330482 DOI: 10.3389/fpls.2022.941388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/27/2022] [Indexed: 06/12/2023]
Abstract
Soil salinity is an important abiotic stress factor that seriously affects the crop growth and yield. Use of plant-derived microorganisms is a promising strategy to alleviate salt stress. In a previous study, the endophytic strain Bacillus altitudinis WR10 isolated from wheat roots showed high salt resistance. In this study, we investigated the efficacy of WR10 in improving the salt tolerance of wheat and its potential mechanisms using a hydroponic test. Under salt stress, WR10 inoculation significantly increased the lengths and dry weights of the roots and shoots, indicating that WR10 improves wheat salt tolerance at the seedling stage. WR10 inoculation significantly reduced Na+ accumulation and enhanced K+, P, and Ca2+ uptake in salt-stressed plants, which can be attributed to the upregulated gene expression of H+-ATPase as well as the P-solubilizing and biofilm-producing characteristics of WR10. At the transcriptional level, L-ascorbate peroxidase (APX), glutathione (GSH) synthetase related to GSH biosynthesis, and phenylpropanoid biosynthesis genes (CYP73A, 4CL, and CAD) were significantly upregulated, whereas those of GSH metabolism genes (glutathione S-transferase and gamma-glutamyltranspeptidase) were significantly downregulated in WR10-applied wheat roots under salt stress. These changes increased the APX activity and GSH levels and resulted in a decrease in hydrogen peroxide levels. Additionally, a decrease in proline content was observed in WR10-inoculated plants under salt stress because of WR10-induced upregulation of proline dehydrogenase gene expression. These results provide supporting evidence that WR10 improves wheat salt tolerance via more than one mechanism and open a window of opportunity for WR10 application in salinized soil.
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Affiliation(s)
- Zonghao Yue
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Yanjuan Chen
- School of Mechanical and Electrical Engineering, Zhoukou Normal University, Zhoukou, China
| | - Yifan Wang
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Limin Zheng
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Qiaoyang Zhang
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Yongchuang Liu
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Chunhong Hu
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Can Chen
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Keshi Ma
- College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China
| | - Zhongke Sun
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
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Azeem MA, Shah FH, Ullah A, Ali K, Jones DA, Khan MEH, Ashraf A. Biochemical Characterization of Halotolerant Bacillus safensis PM22 and Its Potential to Enhance Growth of Maize under Salinity Stress. PLANTS 2022; 11:plants11131721. [PMID: 35807673 PMCID: PMC9268828 DOI: 10.3390/plants11131721] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022]
Abstract
Salinity stress is one of the primary abiotic stresses limiting crop growth and yield. Plants respond to salinity stress with several morphophysiological, molecular, and biochemical mechanisms, however, these mechanisms need to be improved further to cope with salt stress effectively. In this regard, the use of plant growth-promoting (PGP) and halotolerant bacteria is thought to be very efficient for enhancing growth and salinity tolerance in plants. The current study aims to assess Bacillus safensis PM22 for its ability to promote plant growth and resistance to salt. The PM22 produced substantial amounts of exopolysaccharides, indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylic acid deaminase (ACC-deaminase) under saline conditions. Additionally, inoculation of the halotolerant bacteria PM22 reduced the severity of salinity stress in plants and increased root and shoot length at various salt concentrations (0, 180, 240, and 300 mM). Furthermore, PM22-inoculated plants showed markedly enhanced photosynthetic pigment, carotenoid, leaf relative water content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity, salt tolerance index, total soluble sugar, total protein, and ascorbic acid contents compared to non-inoculated control maize plants. PM22 substantially increased antioxidant (enzymatic and non-enzymatic) activities in maize plants, including ascorbate peroxidase, peroxidase, superoxide dismutase, catalase, total flavonoid, and phenol levels. Maize plants inoculated with PM22 also exhibited a significant reduction in electrolyte leakage, hydrogen peroxide, malondialdehyde, glycine betaine, and proline contents compared to non-inoculated control plants. These physiological appearances were further validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), which revealed the upregulation of expression in genes responsible for stress tolerance. In the current investigation, Bacillus safensis PM22 showed plant growth-promoting and salt tolerance attributes and can be utilized as a bio-inoculant to improve yield in salt stress affected areas.
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Affiliation(s)
- Muhammad Atif Azeem
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (M.A.A.); (F.H.S.)
| | - Fahim Hussain Shah
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (M.A.A.); (F.H.S.)
| | - Abid Ullah
- Botany Department, University of Malakand, Chakdara 18800, Pakistan;
| | - Kishwar Ali
- College of General Education, University of Doha for Science and Technology, Arab League Street, Doha P.O. Box 24449, Qatar;
- Correspondence:
| | - David Aaron Jones
- College of Health Sciences, University of Doha for Science and Technology, Arab League Street, Doha P.O. Box 24449, Qatar;
| | - Muhammad Ezaz Hasan Khan
- College of General Education, University of Doha for Science and Technology, Arab League Street, Doha P.O. Box 24449, Qatar;
| | - Azad Ashraf
- College of Engineering, University of Doha for Science and Technology, Arab League Street, Doha P.O. Box 24449, Qatar;
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Abiala MA, Sahoo L. Bacillus aryabhattai enhanced proline content, stabilized membrane and improved growth of cowpea under NaCl-induced salinity stress. J Appl Microbiol 2022; 133:1520-1533. [PMID: 35686652 DOI: 10.1111/jam.15658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 12/12/2021] [Accepted: 05/31/2022] [Indexed: 11/28/2022]
Abstract
AIMS Salinity stress affects the growth of cowpea particularly at the stages of seed germination and early vegetative growth. This study examined the potential of particular stress-tolerant rhizospheric bacteria to improve the growth of cowpea under conditions of salinity stress. METHODS AND RESULTS Two rhizobacillus genotypes, Bacillus filamentosus-C8 and Bacillus aryabhattai-C29 were evaluated for their potentials to protect cowpea under NaCl-induced salinity stress. At 200 mM of NaCl concentration, control (non-inoculated) cowpea was affected, C8 was not able to significantly (p ≤ 0.05) alleviate the effects of salinity stress on cowpea growth while C29 significantly (p ≤ 0.05) reduced leaf wilting, increased chlorophyll content and improved the growth of cowpea plant under stressed condition. Interestingly, C29 significantly (p ≤ 0.05) induced high proline content and stabilized membrane by loss of electrolytes. CONCLUSION Our results indicate that stabilized membrane and enhanced proline content by Bacillus aryabhattai-C29 supported the growth of cowpea under salinity stress condition. SIGNIFICANCE AND IMPACT OF THE STUDY This study revealed that rhizospheric bacteria screened for salinity stress tolerant have potential to be used as an effective bioprotectant for sustainable growth of cowpea under salinity stress condition.
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Affiliation(s)
- Moses Akindele Abiala
- Department of Biological Sciences, College of Basic and Applied Sciences, Mountain Top University, Ogun State, Nigeria.,Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Assam, India
| | - Lingaraj Sahoo
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Assam, India
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Dutta B, Bandopadhyay R. Biotechnological potentials of halophilic microorganisms and their impact on mankind. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2022; 11:75. [PMID: 35669848 PMCID: PMC9152817 DOI: 10.1186/s43088-022-00252-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 05/08/2022] [Indexed: 11/10/2022] Open
Abstract
Background Halophiles are extremophilic organisms represented by archaea, bacteria and eukaryotes that thrive in hypersaline environment. They apply different osmoadaptation strategies to survive in hostile conditions. Habitat diversity of halophilic microorganisms in hypersaline system provides information pertaining the evolution of life on Earth. Main body The microbiome-gut-brain axis interaction contributes greatly to the neurodegenerative diseases. Gut resident halophilic bacteria are used as alternative medication for chronic brain diseases. Halophiles can be used in pharmaceuticals, drug delivery, agriculture, saline waste water treatment, biodegradable plastic production, metal recovery, biofuel energy generation, concrete crack repair and other sectors. Furthermore, versatile biomolecules, mainly enzymes characterized by broad range of pH and thermostability, are suitable candidate for industrial purposes. Reflectance pattern of halophilic archaeal pigment rhodopsin is considered as potential biosignature for Earth-like planets. Short conclusions This review represents important osmoadaptation strategies acquired by halophilic archaea and bacteria and their potential biotechnological applications to resolve present day challenges. Graphical Abstract
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Affiliation(s)
- Bhramar Dutta
- Department of Botany, The University of Burdwan, Purba Bardhaman, West Bengal 713104 India
| | - Rajib Bandopadhyay
- Department of Botany, The University of Burdwan, Purba Bardhaman, West Bengal 713104 India
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The diversity of bacterial endophytes from Iris pseudacorus L. and their plant beneficial traits. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100133. [PMID: 35909614 PMCID: PMC9325737 DOI: 10.1016/j.crmicr.2022.100133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study reports the diversity of cultivable endophytic bacteria associated with yellow iris (Iris pseudacorus L.) by using 16S rRNA gene analysis and their plant beneficial traits. The 16S rRNA sequence similarities of endophytic bacteria isolated from the leaves and roots of yellow iris showed that the isolates belonged to the genera Staphylococcus, Streptomyces, Variovorax, Pantoea, Paenibacillus, Bacillus, Janthinobacterium, Enterobacter, Brevibacterium, Agrobacterium, Rhizobium, Xanthomonas translucens, and Pseudomonas. The endophytic bacteria Pseudomonas gessardii HRT18, Brevibacterium frigoritolerans HRT8, Streptomyces atratus HRT13, and Bacillus toyonensis HST13 exhibited antimicrobial activity against five plant pathogenic fungi Fusarium, Rhizoctonia, Botrytis, Pythium, and Alternaria. They also demonstrated the capability to produce chitinase, protease, glucanase, lipase, HCN, and indole-3-acetic acid (IAA). Thirteen isolates (46%) produced IAA, and the most active IAA producers were Bacillus cereus, Agrobacterium tumefaciens, Agrobacterium vitis, Bacillus megaterium, and Bacillus aryabhattai. The IAA producing bacterial isolates stimulated root and shoot growth of garden cress. Our findings suggest that medicinal plants could be a promising source for isolating plant-beneficial bacteria that can be used to enhance the growth and protect plants against soil-borne pathogens.
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Reang L, Bhatt S, Tomar RS, Joshi K, Padhiyar S, Vyas UM, Kheni JK. Plant growth promoting characteristics of halophilic and halotolerant bacteria isolated from coastal regions of Saurashtra Gujarat. Sci Rep 2022; 12:4699. [PMID: 35304507 PMCID: PMC8933404 DOI: 10.1038/s41598-022-08151-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 01/12/2022] [Indexed: 12/23/2022] Open
Abstract
Halophiles are a class of microorganisms that thrive in environments with very high salt concentrations. The coastal regions of Saurashtra Gujarat host a diverse group of microorganisms including halophilic and halotolerant bacteria that may have plant growth promoting characteristics. Microorganisms with plant growth promoting characteristics are of immense importance in the field of agriculture and the present study was conducted to investigate the characteristics of halophilic and halotolerant bacteria isolated from agricultural soils of coastal regions of Junagadh and Porbandar districts of Saurashtra, Gujarat. A total of 15 isolated strains showed indole acetic acid production, solubilization of phosphate and potash, and nitrogen fixing capacity ranging from 18.77-33.48 μg ml-1, 50.10-106.10%, 180.42-239.92% and 0.170-0.480 g kg-1 of Jensen's agar medium, respectively, while two isolates were also found positive for siderophore production. Besides, nine out of fifteen isolates also showed positive ACC deaminase activity ranging from 0.92-5.78 µM α-ketobutyrate mg-1 h-1. The isolates were further characterized by physiological, microscopic, and biochemical tests. The halophilic and halotolerant bacterial isolates were identified by 16S rRNA gene sequencing as belonging to Halomonas pacifica, H. stenophila, and Bacillus haynesii, B. licheniformis and Oceanobacillus aidingensis respectively. The 16S rRNA partial gene sequence of two isolates belonging to H. pacifica and H. stenophila were submitted to NCBI with accession number MK955347 and MK961217 respectively. The findings of the present investigation showed that isolated bacterial halophiles possess promising plant growth promoting characteristics. Their potential as bioinoculants to alleviate salinity stress in crops and for bioremediation deserves further investigation.
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Affiliation(s)
- Likhindra Reang
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India
| | - Shraddha Bhatt
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India.
| | - Rukam Singh Tomar
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India
| | - Kavita Joshi
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India
| | - Shital Padhiyar
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India
| | - U M Vyas
- Main Oilseed Research Station, Junagadh Agricultural University, Junagadh, Gujarat, India
| | - Jasmin Kumar Kheni
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India
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Salt Stress Tolerance-Promoting Proteins and Metabolites under Plant-Bacteria-Salt Stress Tripartite Interactions. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12063126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The rapid increase in soil salinization has impacted agricultural output and poses a threat to food security. There is an urgent need to focus on improving soil fertility and agricultural yield, both of which are severely influenced by abiotic variables such as soil salinity and sodicity. Abiotic forces have rendered one-third of the overall land unproductive. Microbes are the primary answer to the majority of agricultural production’s above- and below-ground problems. In stressful conditions, proper communication between plants and beneficial microbes is critical for avoiding plant cell damage. Many chemical substances such as proteins and metabolites synthesized by bacteria and plants mediate communication and stress reduction. Metabolites such as amino acids, fatty acids, carbohydrates, vitamins, and lipids as well as proteins such as aquaporins and antioxidant enzymes play important roles in plant stress tolerance. Plant beneficial bacteria have an important role in stress reduction through protein and metabolite synthesis under salt stress. Proper genomic, proteomic and metabolomics characterization of proteins and metabolites’ roles in salt stress mitigation aids scientists in discovering a profitable avenue for increasing crop output. This review critically examines recent findings on proteins and metabolites produced during plant-bacteria interaction essential for the development of plant salt stress tolerance.
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Mutungi PM, Wekesa VW, Onguso J, Kanga E, Baleba SBS, Boga HI. Culturable Bacterial Endophytes Associated With Shrubs Growing Along the Draw-Down Zone of Lake Bogoria, Kenya: Assessment of Antifungal Potential Against Fusarium solani and Induction of Bean Root Rot Protection. FRONTIERS IN PLANT SCIENCE 2022; 12:796847. [PMID: 35222451 PMCID: PMC8864308 DOI: 10.3389/fpls.2021.796847] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Vascular shrubs growing along the draw-down zones of saline lakes must develop adaptive mechanisms to cope with high salinity, erratic environmental conditions, and other biotic and abiotic stresses. Microbial endophytes from plants growing in these unique environments harbor diverse metabolic and genetic profiles that play an important role in plant growth, health, and survival under stressful conditions. A variety of bacterial endophytes have been isolated from salt tolerant plants but their potential applications in agriculture have not been fully explored. To further address this gap, the present study sought to isolate culturable bacterial endophytes from shrubs growing along the draw-down zone of Lake Bogoria, a saline alkaline lake, and examined their functional characteristics and potential in the biocontrol of the bean root rot pathogen, Fusarium solani. We collected shrubs growing within 5 m distance from the shoreline of Lake Bogoria and isolated 69 bacterial endophytes. The endophytic bacteria were affiliated to three different phyla (Firmicutes, Proteobacteria, and Actinobacteria) with a bias in the genera, Bacillus, and they showed no tissue or plant specificity. All selected isolates were positive for catalase enzyme grown in 1.5 M NaCl; three isolates (B23, B19, and B53) produced indole acetic acid (IAA) and only one isolate, B23 did not solubilize phosphate on Pikovskaya agar. Isolates, B19 and B53 exhibited more than 50% of mycelial inhibition in the dual culture assay and completely inhibited the germination of F. solani spores in co-culture assays while two isolates, B07 and B39 had delayed fungal spore germination after an overnight incubation. All isolates were able to establish endophytic association in the roots, stems, and leaves of been seedlings in both seed soaking and drenching methods. Colonization of bean seedlings by the bacterial endophytes, B19 and B53 resulted in the biocontrol of F. solani in planta, reduced disease severity and incidence, and significantly increased both root and shoot biomass compared to the control. Taxonomic identification using 16S rRNA revealed that the two isolates belong to Enterobacter hormaechei subsp., Xiangfangensis and Bacillus megaterium. Our results demonstrate the potential use of these two isolates in the biocontrol of the bean root rot pathogen, F. solani and plant growth promotion.
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Affiliation(s)
- Priscillar Mumo Mutungi
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- Ecological Monitoring Department, Kenya Wildlife Service, Nairobi, Kenya
| | | | - Justus Onguso
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Erustus Kanga
- State Department for Wildlife, Ministry of Tourism and Wildlife, Nairobi, Kenya
| | - Steve B. S. Baleba
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Hamadi Iddi Boga
- Botany Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
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Bioprospecting Desert Plants for Endophytic and Biostimulant Microbes: A Strategy for Enhancing Agricultural Production in a Hotter, Drier Future. BIOLOGY 2021; 10:biology10100961. [PMID: 34681060 PMCID: PMC8533330 DOI: 10.3390/biology10100961] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 01/14/2023]
Abstract
Simple Summary Endophytes are microbes that live inside plants without causing negative effects in their hosts. All land plants are known to have endophytes, and these endophytes have the capacity to be transferred between plants. Taking endophytes from desert plants, which grow in low-nutrient, high-stress environments, and transferring them to crop plants may alleviate some of the challenges being faced by the agricultural industry, such as increasing drought frequency and rising opposition to chemical use in agriculture. Studies have shown that desert endophytes have the capacity to increase nutrient uptake and increase plant resistance to drought and heat stress, salt stress, and pathogen attack. Currently, the agricultural industry focuses on using irrigation, chemical fertilizers, and chemical pesticides to solve such issues, which can be extremely damaging to the environment. While there is still a lot that is unknown about endophytes, particularly desert plant endophytes, current research provides evidence that desert plant endophytes could be an environmentally friendly alternative to the conventional solutions being applied today. Abstract Deserts are challenging places for plants to survive in due to low nutrient availability, drought and heat stress, water stress, and herbivory. Endophytes—microbes that colonize and infect plant tissues without causing apparent disease—may contribute to plant success in such harsh environments. Current knowledge of desert plant endophytes is limited, but studies performed so far reveal that they can improve host nutrient acquisition, increase host tolerance to abiotic stresses, and increase host resistance to biotic stresses. When considered in combination with their broad host range and high colonization rate, there is great potential for desert endophytes to be used in a commercial agricultural setting, especially as croplands face more frequent and severe droughts due to climate change and as the agricultural industry faces mounting pressure to break away from agrochemicals towards more environmentally friendly alternatives. Much is still unknown about desert endophytes, but future studies may prove fruitful for the discovery of new endophyte-based biofertilizers, biocontrol agents, and abiotic stress relievers of crops.
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Salt-Tolerant Compatible Microbial Inoculants Modulate Physio-Biochemical Responses Enhance Plant Growth, Zn Biofortification and Yield of Wheat Grown in Saline-Sodic Soil. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18189936. [PMID: 34574855 PMCID: PMC8467820 DOI: 10.3390/ijerph18189936] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/10/2021] [Accepted: 09/18/2021] [Indexed: 11/17/2022]
Abstract
A wide range of root-associated mutualistic microorganisms have been successfully applied and documented in the past for growth promotion, biofertilization, biofortification and biotic and abiotic stress amelioration in major crops. These microorganisms include nitrogen fixers, nutrient mobilizers, bio-remediators and bio-control agents. The present study aimed to demonstrate the impact of salt-tolerant compatible microbial inoculants on plant growth; Zn biofortification and yield of wheat (Triticum aestivum L.) crops grown in saline-sodic soil and insight of the mechanisms involved therein are being shared through this paper. Field experiments were conducted to evaluate the effects of Trichoderma harzianum UBSTH-501 and Bacillus amyloliquefaciens B-16 on wheat grown in saline-sodic soil at Research Farm, ICAR-Indian Institute of Seed Sciences, Kushmaur, India. The population of rhizosphere-associated microorganisms changed dramatically upon inoculation of the test microbes in the wheat rhizosphere. The co-inoculation induced a significant accumulation of proline and total soluble sugar in wheat at 30, 60, 90 and 120 days after sowing as compared to the uninoculated control. Upon quantitative estimation of organic solutes and antioxidant enzymes, these were found to have increased significantly in co-inoculated plants under salt-stressed conditions. The application of microbial inoculants enhanced the salt tolerance level significantly in wheat plants grown in saline-sodic soil. A significant increase in the uptake and translocation of potassium (K+) and calcium (Ca2+) was observed in wheat co-inoculated with the microbial inoculants, while a significant reduction in sodium (Na+) content was recorded in plants treated with both the bio-agents when compared with the respective uninoculated control plants. Results clearly indicated that significantly higher expression of TaHKT-1 and TaNHX1 in the roots enhances salt tolerance effectively by maintaining the Na+/K+ balance in the plant tissue. It was also observed that co-inoculation of the test inoculants increased the expression of ZIP transporters (2–3.5-folds) which ultimately led to increased biofortification of Zn in wheat grown in saline-sodic soil. Results suggested that co-inoculation of T. harzianum UBSTH-501 and B. amyloliquefaciens B-16 not only increased plant growth but also improved total grain yield along with a reduction in seedling mortality in the early stages of crop growth. In general, the present investigation demonstrated the feasibility of using salt-tolerant rhizosphere microbes for plant growth promotion and provides insights into plant-microbe interactions to ameliorate salt stress and increase Zn bio-fortification in wheat.
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Saleem S, Iqbal A, Ahmed F, Ahmad M. Phytobeneficial and salt stress mitigating efficacy of IAA producing salt tolerant strains in Gossypium hirsutum. Saudi J Biol Sci 2021; 28:5317-5324. [PMID: 34466110 PMCID: PMC8381066 DOI: 10.1016/j.sjbs.2021.05.056] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/20/2021] [Accepted: 05/20/2021] [Indexed: 11/27/2022] Open
Abstract
Salinity is one of the major agricultural concern that significantly limits the crop productivity. The plant growth promoting rhizobacteria (PGPR) may contribute in sustainable crop production under salt stress. The current study was designed to isolate the Indole Acetic Acid (IAA) producing salt tolerant PGPR to promote the growth of cotton (Gossypium hirsutum, FH-142) and induce its salt stress tolerance. Ten Salt Tolerant (ST) bacterial strains were screened for their PGP trait in vitro and evaluated for their beneficial effect on cotton plants growth by plant–microbe interaction assay in lab and under natural condition. GC–MS analysis of the metabolites of the selected bacterial strains confirmed the presence of indolic compounds like indole, indole-3-butyramide, benzylmalonic acid and 4-methyl-2-pyrrolidinone. The bacterial isolates ST4, ST5, ST6, ST15, ST16, ST17, ST18, ST20, ST22 and ST25 were identified as Bacillus sp., B. sonorensis, B. cereus, B. subtilis, Brevibacillus sp. B. safensis, B. paramycoides, Bacillus sp., B. cereus and B. tequilensis respectively on the basis of 16S rDNA sequencing. Bacteria inoculated plants had a significant (P < 0.05) increase in percentage germination up to (31%), root length (17%) and shoot length (34%) in lab while in wire house pot experiments, maximum enhancement in root length (31%) and shoot length (29%) was observed. ST bacterial strains inoculation improved the chlorophyll content index (34%), relative water content (36%), leaf area (33%), absorption of K+ (28%) and decreased the uptake of Na+ (58%) from soil in plants under salt stress over control in pot experiment. These ST PGPR have the potential to act as plant defense agents by enhancing plant growth, productivity, and tolerance in saline environment.
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Affiliation(s)
- Sarwat Saleem
- Department of Microbiology and Molecular Genetics, Matital Campus, The Women University Multan, P.O. Box No. 60000, Multan, Pakistan
| | - Atia Iqbal
- Department of Microbiology and Molecular Genetics, Matital Campus, The Women University Multan, P.O. Box No. 60000, Multan, Pakistan
| | - Fiaz Ahmed
- Department of Plant Physiology/Chemistry Section, Central Cotton Research Institute Multan, P.O. Box No. 572, Old Shujabad Road, Multan, Pakistan
| | - Mehboob Ahmad
- Department of Microbiology and Molecular Genetics, Quaid-e-Azam Campus, University of the Punjab, P.O. Box No. 54590, Lahore, Pakistan
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Potential of Halophilic/Halotolerant Bacteria in Enhancing Plant Growth Under Salt Stress. Curr Microbiol 2021; 78:3708-3719. [PMID: 34427735 DOI: 10.1007/s00284-021-02637-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 08/19/2021] [Indexed: 01/16/2023]
Abstract
In the current study, fourteen bacterial strains were obtained in salt contaminated soils. The identification and characterization of the bacterial strains were performed by conventional and molecular techniques. According to the results of 16S rRNA gene sequence analysis, five genera (Bacillus, Staphylococcus, Oceanobacillus, Exiguobacterium, and Halobacillus) were identified with a homology of equal to 99% or higher similarity. Afterward, these fourteen halotolerant/halophilic bacterial strains were investigated for their plant growth promoting (PGP) traits including production of indole-3-acetic acid (IAA) and siderophore, activity of 1-aminocyclopropane-1-carboxylate (ACC) deaminase, fixation of nitrogen, and phosphate solubilization potential. Five of the bacterial strains possessing PGP traits were tested for their effects on the growth of a salt sensitive plant (wheat) in a hydroponic system under salt stress (200 mM). Inoculation of five bacterial strains under salt stress significantly enhanced plant weight (Triticum aestivum) ranged from 71.18 to 89.04%. Salt stress amelioration potential of Oceanobacillus picturae and Staphylococcus succinus on T. aestivum has been shown for the first time in this study. In non-saline soil, the promising effect of plant growth bacteria is clear; however, in saline soil, the use of PGP halophilic and halotolerant bacteria can increase the productivity of salt sensitive plants. Therefore, the novel halophilic and halotolerant bacteria that promote plant growth can be developed for agricultural uses in saline soils.
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Thalassobacillus, a genus of extreme to moderate environmental halophiles with biotechnological potential. World J Microbiol Biotechnol 2021; 37:147. [PMID: 34363544 DOI: 10.1007/s11274-021-03116-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/29/2021] [Indexed: 01/09/2023]
Abstract
Thalassobacillus is a moderately halophilic genus that has been isolated from several sites worldwide, such as hypersaline lakes, saline soils, salt flats, and volcanic mud. Halophilic bacteria have provided functional stable biomolecules in harsh conditions for industrial purposes. Despite its potential biotechnological applications, Thalassobacillus has not been fully characterized yet. This review describes the Thalassobacillus genus, with the few species reported, pointing out its possible applications in enzymes (amylases, cellulases, xylanases, and others), biosurfactants, bioactive compounds, biofuels production, bioremediation, and plant growth promotion. The Thalassobacillus genus represents a little-explored biological resource but with a high potential.
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Halotolerant Microbial Consortia for Sustainable Mitigation of Salinity Stress, Growth Promotion, and Mineral Uptake in Tomato Plants and Soil Nutrient Enrichment. SUSTAINABILITY 2021. [DOI: 10.3390/su13158369] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Salinity significantly impacts the growth, development, and reproductive biology of various crops such as vegetables. The cultivable area is reduced due to the accumulation of salts and chemicals currently in use and is not amenable to a large extent to avoid such abiotic stress factors. The addition of microbes enriches the soil without any adverse effects. The effects of microbial consortia comprising Bacillus sp., Delftia sp., Enterobacter sp., Achromobacter sp., was evaluated on the growth and mineral uptake in tomatoes (Solanum Lycopersicum L.) under salt stress and normal soil conditions. Salinity treatments comprising Ec 0, 2, 5, and 8 dS/m were established by mixing soil with seawater until the desired Ec was achieved. The seedlings were transplanted in the pots of the respective pH and were inoculated with microbial consortia. After sufficient growth, these seedlings were transplanted in soil seedling trays. The measurement of soil minerals such as Na, K, Ca, Mg, Cu, Mn, and pH and the Ec were evaluated and compared with the control 0 days, 15 days, and 35 days after inoculation. The results were found to be non-significant for the soil parameters. In the uninoculated seedlings’ (control) seedling trays, salt treatment significantly affected leaf, shoot, root dry weight, shoot height, number of secondary roots, chlorophyll, and mineral contents. While bacterized seedlings sown under saline soil significantly increased leaf (105.17%), shoot (105.62%), root (109.06%) dry weight, leaf number (75.68%), shoot length (92.95%), root length (146.14%), secondary roots (91.23%), and chlorophyll content (−61.49%) as compared to the control (without consortia). The Na and K intake were higher even in the presence of the microbes, but the beneficial effect of the microbe helps plants sustain in the saline environment. The inoculation of microbial consortia produced more secondary roots, which accumulate more minerals and transport substances to the different parts of the plant; thus, it produced higher biomass and growth. Results of the present study revealed that the treatment with microbial consortia could alleviate the deleterious effects of salinity stress and improve the growth of tomato plants under salinity stress. Microbial consortia appear to be the best alternative and cost-effective and sustainable approach for managing soil salinity and improving plant growth under salt stress conditions.
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Plant Growth Promoting Rhizobacteria, Arbuscular Mycorrhizal Fungi and Their Synergistic Interactions to Counteract the Negative Effects of Saline Soil on Agriculture: Key Macromolecules and Mechanisms. Microorganisms 2021; 9:microorganisms9071491. [PMID: 34361927 PMCID: PMC8307984 DOI: 10.3390/microorganisms9071491] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/05/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022] Open
Abstract
Soil saltiness is a noteworthy issue as it results in loss of profitability and development of agrarian harvests and decline in soil health. Microorganisms associated with plants contribute to their growth promotion and salinity tolerance by employing a multitude of macromolecules and pathways. Plant growth promoting rhizobacteria (PGPR) have an immediate impact on improving profitability based on higher crop yield. Some PGPR produce 1-aminocyclopropane-1-carboxylic (ACC) deaminase (EC 4.1.99.4), which controls ethylene production by diverting ACC into α-ketobutyrate and ammonia. ACC deaminase enhances germination rate and growth parameters of root and shoot in different harvests with and without salt stress. Arbuscular mycorrhizal fungi (AMF) show a symbiotic relationship with plants, which helps in efficient uptake of mineral nutrients and water by the plants and also provide protection to the plants against pathogens and various abiotic stresses. The dual inoculation of PGPR and AMF enhances nutrient uptake and productivity of several crops compared to a single inoculation in both normal and stressed environments. Positively interacting PGPR + AMF combination is an efficient and cost-effective recipe for improving plant tolerance against salinity stress, which can be an extremely useful approach for sustainable agriculture.
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Amini Hajiabadi A, Mosleh Arani A, Ghasemi S, Rad MH, Etesami H, Shabazi Manshadi S, Dolati A. Mining the rhizosphere of halophytic rangeland plants for halotolerant bacteria to improve growth and yield of salinity-stressed wheat. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 163:139-153. [PMID: 33845330 DOI: 10.1016/j.plaphy.2021.03.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
In this study, the effects of three halotolerant rhizobacterial isolates AL, HR, and SB, which are able to grow at a salinity level of 1600 mM NaCl, with multiple plant growth promoting (PGP) traits on some seed and forage quality attributes, and vegetative, reproductive, biochemical and physiological characteristics of wheat plant irrigated with saline water (0, 40, 80, and 160 mM NaCl) were investigated. The ability of halotolerant bacterial isolates to produce PGP traits was affected by salinity levels, depending upon the bacterial isolates. Salinity stress significantly affected the yield, quality, and growth of wheat by modifying the morpho-physiological and biochemical traits of the exposed plants. However, all three bacterial isolates, especially isolate AL, significantly improved the biochemical (an increase in K+/Na+ ratio by 55%, plant P content by 50%, and plant Ca content by 31%), morphological (an increase in stem dry weight by 52%, root dry weight by 44%, spike dry weight by 34%, and grain dry weight by 43%), and physiological (an increase in leaf proline content by 50% and total phenol in leaf by 42%) attributes of wheat and aided the plant to tolerate salinity stress in contrast to un-inoculated plant. Plants inoculated with bacterial isolates showed significantly improved seed amylose by 36%, leaf crude protein by 30%, leaf metabolic energy by 37%, and leaf water-soluble sugar content by 34%. Among the measured PGP and plant attributes, bacterial auxin and plant K content were of key importance in increasing reproductive performance of wheat. The bacterial isolates AL, HR, and SB were identified as Bacillus safensis, B. pumilus, and Zhihengliuella halotolerans, respectively, based on 16 S rDNA sequence. The study reveals that application of halotolerant plant growth-promoting rhizobacteria isolated from halophytic rangeland plants can be a cost effective and ecological sustainable method to improve wheat productivity, especially the attributes related to seed and forage quality, under salinity stress conditions.
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Affiliation(s)
| | - Asghar Mosleh Arani
- Department of Environmental Sciences, Faculty of Natural Resources, Yazd University, Yazd, Iran.
| | - Somayeh Ghasemi
- Department of Soil Sciences, Faculty of Natural Resources, Yazd University, Yazd, Iran
| | - Mohammad Hadi Rad
- Forest and Rangeland Division, Yazd Agricultural and Natural Resource Research and Education Center, Yazd, Iran
| | - Hassan Etesami
- Department of Soil Science, University of Tehran, Karaj, Iran.
| | | | - Ali Dolati
- Faculty of Mathematics, Department of Statistics, Yazd University, Yazd, Iran
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Characterization of Plant Growth-Promoting Traits and Inoculation Effects on Triticum durum of Actinomycetes Isolates under Salt Stress Conditions. SOIL SYSTEMS 2021. [DOI: 10.3390/soilsystems5020026] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.
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Analysis of Gene Expression Changes in Plants Grown in Salty Soil in Response to Inoculation with Halophilic Bacteria. Int J Mol Sci 2021; 22:ijms22073611. [PMID: 33807153 PMCID: PMC8036567 DOI: 10.3390/ijms22073611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 12/24/2022] Open
Abstract
Soil salinity is an increasing problem facing agriculture in many parts of the world. Climate change and irrigation practices have led to decreased yields of some farmland due to increased salt levels in the soil. Plants that have tolerance to salt are thus needed to feed the world's population. One approach addressing this problem is genetic engineering to introduce genes encoding salinity, but this approach has limitations. Another fairly new approach is the isolation and development of salt-tolerant (halophilic) plant-associated bacteria. These bacteria are used as inoculants to stimulate plant growth. Several reports are now available, demonstrating how the use of halophilic inoculants enhance plant growth in salty soil. However, the mechanisms for this growth stimulation are as yet not clear. Enhanced growth in response to bacterial inoculation is expected to be associated with changes in plant gene expression. In this review, we discuss the current literature and approaches for analyzing altered plant gene expression in response to inoculation with halophilic bacteria. Additionally, challenges and limitations to current approaches are analyzed. A further understanding of the molecular mechanisms involved in enhanced plant growth when inoculated with salt-tolerant bacteria will significantly improve agriculture in areas affected by saline soils.
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Ha-Tran DM, Nguyen TTM, Hung SH, Huang E, Huang CC. Roles of Plant Growth-Promoting Rhizobacteria (PGPR) in Stimulating Salinity Stress Defense in Plants: A Review. Int J Mol Sci 2021; 22:3154. [PMID: 33808829 PMCID: PMC8003591 DOI: 10.3390/ijms22063154] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/14/2022] Open
Abstract
To date, soil salinity becomes a huge obstacle for food production worldwide since salt stress is one of the major factors limiting agricultural productivity. It is estimated that a significant loss of crops (20-50%) would be due to drought and salinity. To embark upon this harsh situation, numerous strategies such as plant breeding, plant genetic engineering, and a large variety of agricultural practices including the applications of plant growth-promoting rhizobacteria (PGPR) and seed biopriming technique have been developed to improve plant defense system against salt stress, resulting in higher crop yields to meet human's increasing food demand in the future. In the present review, we update and discuss the advantageous roles of beneficial PGPR as green bioinoculants in mitigating the burden of high saline conditions on morphological parameters and on physio-biochemical attributes of plant crops via diverse mechanisms. In addition, the applications of PGPR as a useful tool in seed biopriming technique are also updated and discussed since this approach exhibits promising potentials in improving seed vigor, rapid seed germination, and seedling growth uniformity. Furthermore, the controversial findings regarding the fluctuation of antioxidants and osmolytes in PGPR-treated plants are also pointed out and discussed.
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Affiliation(s)
- Dung Minh Ha-Tran
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei 11529, Taiwan;
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; (T.T.M.N.); (S.-H.H.)
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Trinh Thi My Nguyen
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; (T.T.M.N.); (S.-H.H.)
| | - Shih-Hsun Hung
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; (T.T.M.N.); (S.-H.H.)
- Department of Horticulture, National Chung Hsing University, Taichung 40227, Taiwan
| | - Eugene Huang
- College of Agriculture and Natural Resources, National Chung Hsing University, Taichung 40227, Taiwan;
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; (T.T.M.N.); (S.-H.H.)
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan
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Rhizospheric Phosphate Solubilizing Bacillus atrophaeus GQJK17 S8 Increases Quinoa Seedling, Withstands Heavy Metals, and Mitigates Salt Stress. SUSTAINABILITY 2021. [DOI: 10.3390/su13063307] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction of quinoa (Chenopodium quinoa willd.), a gluten-free nutritious pseudo-cereal, outside its traditional growing areas exposed it to seedling damping-off. Here, we isolated eleven phosphate-solubilizing bacteria from the quinoa rhizosphere and assessed their effect on germination and seedlings growth. All isolates solubilized phosphate, produced indole3-acetic acid, hydrocyanic acid, siderophores, and ammonia. Genotypic analysis revealed that our strains are related to the genus of Bacillus, Pseudomonas, and Enterobacter. Strains Enterobacter asburiae (QD14, QE4, QE6, and QE16), Enterobacter sp. QE3, and Enterobacter hormaechei QE7 withstood 1.5 mg·L−1 of cadmium sulfate, 0.5 mg·mL−1 of nickel nitrate, and 1 mg·mL−1 of copper sulfate. Moreover, all strains solubilized zinc from ZnO; P. Stutzeri QD1 and E. asburiae QD14 did not solubilize Zn3(PO4)2 and CO3Zn, whereas CO3Zn was not solubilized by E. asburiae QE16. Bacillus atrophaeus S8 tolerated 11% NaCl. P. frederiksbergensis S6 and Pseudomonas sp. S7 induced biofilm formation. Anti-fusarium activity was demonstrated for E.asburiae QE16, P. stutzeri QD1, P. frederiksbergensis S6, Pseudomonas sp. S7, and B. atrophaeus S8. Lastly, inoculation of quinoa seeds with B. atrophaeus S8 and E. asburiae QB1 induced the best germination rate and seedling growth, suggesting their potential use as inoculants for salty and heavy metal or zinc contaminated soils.
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Ranawat B, Bachani P, Singh A, Mishra S. Enterobacter hormaechei as Plant Growth-Promoting Bacteria for Improvement in Lycopersicum esculentum. Curr Microbiol 2021; 78:1208-1217. [PMID: 33625569 DOI: 10.1007/s00284-021-02368-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
Humans have been using natural resources for their daily life support. The population boom around the world has created a need to develop a new technique for increased crop production. Chemical fertilizers used in modern agriculture lead to pollution, besides increase in farming costs. To solve this problem, the present study deals with a natural halotolerant Enterobacter hormaechei which can fix N and solubilize desired macronutrients P and K. Enterobacter hormaechei was able to solubilize K-feldspar into potassium (97.5 ± 1.76 mg/L), tri-calcium phosphate into phosphate (99.7 ± 02 µg/mL) and it also produced IAA (47.87 ± 0.85 mg/L). Experiments, including morphological and chemical analysis, have provided a new growth pattern in Lycopersicum esculentum. Tomato seeds (Lycopersicum esculentum) treated with Enterobacter hormaechei enhanced biomass and an increase in shoot length when compared to control. It enhanced not only plant growth but modified the root architecture leading to improved crop productivity.
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Affiliation(s)
- Bablesh Ranawat
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India.,Applied Phycology and Biotechnology Division, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India
| | - Pooja Bachani
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India.,Applied Phycology and Biotechnology Division, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India
| | - Aneesha Singh
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India. .,Applied Phycology and Biotechnology Division, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India.
| | - Sandhya Mishra
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India.,Applied Phycology and Biotechnology Division, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364002, India
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Xie J, Yan Z, Wang G, Xue W, Li C, Chen X, Chen D. A Bacterium Isolated From Soil in a Karst Rocky Desertification Region Has Efficient Phosphate-Solubilizing and Plant Growth-Promoting Ability. Front Microbiol 2021; 11:625450. [PMID: 33597933 PMCID: PMC7882523 DOI: 10.3389/fmicb.2020.625450] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/28/2020] [Indexed: 11/21/2022] Open
Abstract
Phosphorus in the soil accessible to plants can easily be combined with calcium ion, the content of which is high in karst rocky desertification (KRD) regions, thereby resulting in a low utilization efficiency of phosphorus. The application of phosphate-solubilizing bacteria (PSB) from the KRD region would facilitate enhanced phosphate availability in the soil. In the present study, the strains belonging to Acinetobacter, Paraburkholderia, and Pseudomonas with efficient phosphate-solubilizing ability were isolated from fruit tree rhizosphere soils in KRD regions. Particularly, Acinetobacter sp. Ac-14 had a sustained and stable phosphate-solubilizing ability (439–448 mg/L, 48–120 h). Calcium carbonate decreased the phosphate-solubilizing ability in liquid medium; however, it did not affect the solubilization index in agar-solidified medium. When cocultivated with Arabidopsis thaliana seedling, Ac-14 increased the number of lateral roots, fresh weight, and chlorophyll content of the seedlings. Metabolomics analysis revealed that Ac-14 could produce 23 types of organic acids, majorly including gluconic acid and D-(-)-quinic acid. Expression of Ac-14 glucose dehydrogenase gene (gcd) conferred Pseudomonas sp. Ps-12 with a sustained and stable phosphate-solubilizing ability, suggesting that the production of gluconic acid is an important mechanism that confers phosphate solubilization in bacteria. Moreover, Ac-14 could also produce indole acetic acid and ammonia. Collectively, the isolated Ac-14 from KRD regions possess an efficient phosphate-solubilizing ability and plant growth-promoting effect which could be exploited for enhancing phosphorus availability in KRD regions. This study holds significance for the improvement of soil fertility and agricultural sustainable development in phosphorus-deficient KRD regions.
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Affiliation(s)
- Jinge Xie
- Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Zongqiang Yan
- Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Guifen Wang
- Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Wenzhi Xue
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Cong Li
- Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiwen Chen
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Defu Chen
- Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
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Strategy of Salt Tolerance and Interactive Impact of Azotobacter chroococcum and/or Alcaligenes faecalis Inoculation on Canola ( Brassica napus L.) Plants Grown in Saline Soil. PLANTS 2021; 10:plants10010110. [PMID: 33430173 PMCID: PMC7825586 DOI: 10.3390/plants10010110] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 12/11/2022]
Abstract
A pot experiment was designed and performed in a completely randomized block design (CRBD) to determine the main effect of two plant growth-promoting rhizobacteria (PGPR) and their co-inoculation on growth criteria and physio-biochemical attributes of canola plants (Brassica napus L.) plant grown in saline soil. The results showed that inoculation with two PGPR (Azotobacter chroococcum and/or Alcaligenes faecalis) energized the growth parameters and photosynthetic pigments of stressed plants. Moreover, soluble sugars’ and proteins’ contents were boosted due to the treatments mentioned above. Proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) contents were markedly declined. At the same time, antioxidant enzymes, viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD), were augmented due to the inoculation with Azotobacter chroococcum and/or Alcaligenes faecalis. Regarding minerals’ uptake, there was a decline in sodium (Na) and an increase in nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) uptake due to the application of either individual or co-inoculation with the mentioned bacterial isolates. This study showed that co-inoculation with Azotobacter chroococcum and Alcaligenes faecalis was the most effective treatment and could be considered a premium tool used in facing environmental problems, especially saline soils.
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Zia H, Ayub MA, Fattah El Baroudy AAE, Rehman MZU, Khalid H, Haq AU, Umar W, Ahmad Z. Microbial associations in ecological reclamation and restoration of marginal lands. MICROBES IN LAND USE CHANGE MANAGEMENT 2021:239-266. [DOI: 10.1016/b978-0-12-824448-7.00014-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Physiological and Biochemical Behaviors of Date Palm Vitroplants Treated with Microbial Consortia and Compost in Response to Salt Stress. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10238665] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The main challenge of the agricultural sector is to develop new ecological technologies that increase the yields and the tolerance of crops to abiotic constraints, especially in arid areas. The objective of this study was to test the potential roles of biofertilizers, namely, arbuscular mycorrhizal fungi (AMF), a native AMF consortium (AMF1) and an exotic AMF strain (AMF2); plant growth-promoting rhizobacteria (PGPR); and compost (comp), applied separately or in combination, in improving the tolerance of date palm vitroplants to salt stress. Plants were grown under non-stressed (0 mM NaCl) or stressed conditions (120 and 240 mM NaCl). Salt stress negatively affected growth and physiological parameters. However, biofertilizers used alone or in combination increased these traits in either the presence or absence of salinity. The two tripartite combinations PGPR+AMF1+Comp and PGPR+AMF2+Comp efficiently increased plant height compared to the controls, with respective enhancements of 47% and 48% under non-stressed conditions (0 mM), 44% and 43% under 120 mM NaCl and 42% and 41% under 240 mM NaCl. Moreover, under 240 mM NaCl level, the PGPR, AMF1+Comp and PGPR+AMF1+Comp treatments improved the shoot dry weight by 128%, 122% and 113% respectively compared to the stressed control plants submitted to 240 mM NaCl. The tripartite combinations PGPR+AMF1/AMF2+Comp improved salt stress tolerance of plants by increasing plant growth, accumulation of osmotic adjustment compounds and antioxidant enzyme activity compared to control plants and the other treatments.
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Yasmeen T, Ahmad A, Arif MS, Mubin M, Rehman K, Shahzad SM, Iqbal S, Rizwan M, Ali S, Alyemeni MN, Wijaya L. Biofilm forming rhizobacteria enhance growth and salt tolerance in sunflower plants by stimulating antioxidant enzymes activity. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 156:242-256. [PMID: 32979797 DOI: 10.1016/j.plaphy.2020.09.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/04/2020] [Indexed: 05/25/2023]
Abstract
Salinity stress is one of the major environmental stresses that impose global socio-economic impacts, as well as hindering crop productivity. Halotolerant plant growth-promoting rhizobacteria (PGPR) having potential to cope with salinity stress can be employed to counter this issue in eco-friendly way. In the present investigation, halotolerant PGPR strains, AP6 and PB5, were isolated from saline soil and characterized for their biochemical, molecular and physiological traits. Sequencing of 16 S rRNA gene and comparative analysis confirmed the taxonomic affiliation of AP6 with Bacillus licheniformis and PB5 with Pseudomonas plecoglossicida. The study was carried out in pots with different levels of induced soil salinity viz. 0, 5, 10 and 15 dSm-1 to evaluate the potential of bacterial inoculants in counteracting salinity stress in sunflower at different plant growth stages (30, 45 and 60 days after sowing). Both the bacterial inoculants were capable of producing indole acetic acid and biofilm, solubilizing inorganic rock phosphate, and also expressed ACC deaminase activity. The PGPR inoculated plants showed significantly higher fresh and dry biomass, plant height, root length and yield plant-1. Ameliorative significance of applied bacterial inoculants was also evidenced by mitigating oxidative stress through upregulation of catalase (CAT), superoxide dismutase (SOD) and guaiacol peroxidase (GPX) antioxidant enzymes. Increase in photosynthetic pigments, gas exchange activities and nutrient uptake are crucial salt stress adaptations, which were enhanced with the inoculation of salt tolerant biofilm producing PGPR in sunflower plants. Although increase in salinity stress levels has gradually decreased the plant's output compared to non-salinized plants, the plants inoculated with PGPR confronted salinity stress in much better way than uninoculated plants. Owing to the wide action spectrum of these bacterial inoculants, it was concluded that these biofilm PGPR could serve as effective bioinoculants and salinity stress alleviator for sunflower (oil seed crop) by increasing crop productivity in marginalized agricultural systems.
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Affiliation(s)
- Tahira Yasmeen
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan.
| | - Aqeel Ahmad
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan
| | - Muhammad Saleem Arif
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan
| | - Muhammad Mubin
- Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Pakistan
| | - Khadija Rehman
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan
| | - Sher Muhammad Shahzad
- Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha, 40100, Punjab, Pakistan
| | - Shahid Iqbal
- Key Laboratory for Economic Plants and Biotechnology, Centre for Mountain Futures CMF, East and Central Asia Regional Office, World Agroforestry Centre ICRAF, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, CN 650201, China
| | - Muhammad Rizwan
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan
| | - Shafaqat Ali
- Department of Environmental Sciences and Engineering, Government College University Faisalabad, 38000, Pakistan; Department of Biological Sciences and Technology, China Medical University, Taichung, 40402, Taiwan.
| | - Mohammed Nasser Alyemeni
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Leonard Wijaya
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
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Alexander A, Singh VK, Mishra A. Halotolerant PGPR Stenotrophomonas maltophilia BJ01 Induces Salt Tolerance by Modulating Physiology and Biochemical Activities of Arachis hypogaea. Front Microbiol 2020; 11:568289. [PMID: 33162950 PMCID: PMC7591470 DOI: 10.3389/fmicb.2020.568289] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/22/2020] [Indexed: 01/25/2023] Open
Abstract
Arachis hypogaea (Peanut) is one of the most important cash crops grown for food and oil production. Salinity is a major constraint for loss of peanut productivity, and halotolerant plant growth promoting bacteria not only enhance plant-growth but also provide tolerance against salt stress. The potential of halotolerant bacterium Stenotrophomonas maltophilia BJ01 isolated from saline-soil was explored to enhance the growth of peanut plants under salt stress conditions. Interaction of S. maltophilia BJ01 enhances the growth of the peanut plants and protects photosynthetic pigments under salt stress. Lower electrolyte leakage (about 20%), lipid peroxidation (2.1 μmol g-1 Fw), proline (2.9 μg mg-1 Fw) content and H2O2 (55 μmol g-1 Fw) content were observed in plants, co-cultivated with PGPR compared to untreated plants under stress condition. The growth hormone auxin (0.4 mg g-1 Fw) and total amino acid content (0.3 mg g-1 Fw) were enhanced in plants co-cultivated with PGPR under stress conditions. Overall, these results indicate the beneficial effect of S. maltophilia BJ01 on peanut plants under salt (100 mM NaCl) stress conditions. In conclusion, bacterium S. maltophilia BJ01 could be explored further as an efficient PGPR for growing legumes especially peanuts under salt stress conditions. However, a detailed agronomic study would be needed to ascertain its commercial role.
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Affiliation(s)
- Ankita Alexander
- Division of Applied Phycology and Biotechnology, CSIR – Central Salt and Marine Chemicals Research Institute, Bhavnagar, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR, Ghaziabad, India
| | - Vijay K. Singh
- Division of Applied Phycology and Biotechnology, CSIR – Central Salt and Marine Chemicals Research Institute, Bhavnagar, India
| | - Avinash Mishra
- Division of Applied Phycology and Biotechnology, CSIR – Central Salt and Marine Chemicals Research Institute, Bhavnagar, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR, Ghaziabad, India
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Bioprospecting of a Novel Plant Growth-Promoting Bacterium Bacillus Altitudinis KP-14 for Enhancing Miscanthus × giganteus Growth in Metals Contaminated Soil. BIOLOGY 2020; 9:biology9090305. [PMID: 32972004 PMCID: PMC7564662 DOI: 10.3390/biology9090305] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/18/2020] [Accepted: 09/20/2020] [Indexed: 12/16/2022]
Abstract
Simple Summary Marginal land represents poor soil with low agricultural characteristics and crop productivity, which is sometimes additionally contaminated. The exploitation of marginal land for normal agriculture is not possible but it suitable for cultivation of energy crops, especially Miscanthus × giganteus (Mxg), however, the harvest biomass value in such land is lower. The produced Mxg biomass can be converted to alternative energy like biofuel and biogas, or used for production of other value-added products like insulation fibers, building materials or paper, etc. It is well known fact that plant growth-promoting bacteria are beneficial for stimulating the overall development of plants even under stress conditions. In the current study, a number of strains were isolated from the metal-contaminated post-mining land, identified, biochemically characterized, and evaluated for abiotic stress tolerance: pH, temperature, salinity, and heavy metal (lead). Among different isolates, the multiple abiotic stress-tolerant plant growth-promoting bacteria Bacillus altitudinis KP-14 showed the best properties. Its effect on the growth of Mxg under the severe stress of metal-contaminated soil was evaluated. It was found that selected bacterial strain KP-14 significantly enhanced the biomass production. The overall results suggested that B. altitudinis KP-14 can be recommended as a potent biofertilizer for marginal lands. Abstract Use of plant growth-promoting bacteria (PGPB) for cultivation of the biofuel crop Miscanthus × giganteus (Mxg) in post-military and post-mining sites is a promising approach for the bioremediation of soils contaminated by metals. In the present study, PGPB were isolated from contaminated soil and screened for tolerance against abiotic stresses caused by salinity, pH, temperature, and lead (Pb). Selected strains were further assessed and screened for plant growth-promoting attributes. The isolate showing the most potential, Bacillus altitudinis KP-14, was tested for enhancement of Mxg growth in contaminated soil under greenhouse conditions. It was found to be highly tolerant to diverse abiotic stresses, exhibiting tolerance to salinity (0–15%), pH (4–8), temperature (4–50 °C), and Pb (up to 1200 ppm). The association of B. altitudinis KP-14 with Mxg resulted in a significant (p ≤ 0.001) impact on biomass enhancement: the total shoot and dry root weights were significantly enhanced by 77.7% and 55.5%, respectively. The significant enhancement of Mxg biomass parameters by application of B. altitudinis KP-14 strongly supports the use of this strain as a biofertilizer for the improvement of plant growth in metal-contaminated soils.
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