1
|
Kumari K, Sharma PK, Singh RP. The transcriptome response of Enterobacter sp. S-33 is modulated by low pH-stress. Genes Genomics 2024; 46:671-687. [PMID: 38687436 DOI: 10.1007/s13258-024-01513-x] [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: 06/13/2023] [Accepted: 03/26/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND Acidic environments naturally occur worldwide and uncontrolled use of agricultural practices may also cause acidification of soils. The development of acidic conditions disturbs the establishment of efficient microbial populations in their natural niches. The survival of Enterobacter species under acidic stress remains poorly understood. OBJECTIVE This study aimed to investigate the survival of an environmental isolate Enterobacter sp. S-33 under acidic stress and to identify the various genes involved in stress protection at the global gene transcription level. The obtained results provide new targets that will allow understanding the in-depth mechanisms involved in the adaptation of bacteria to environmental pH changes. METHODS We used the next-generation sequencing (NGS) method to analyze the expression (up-regulation & down-regulation) of genes under varying pH conditions. RESULTS A total of 4214 genes were differentially expressed under acidic conditions (pH 5.0), with 294 up-regulated and 167 down-regulated. At pH 6.0, 50 genes were significantly expressed, of which 34 and 16 were identified as up-regulated and down-regulated, respectively. Many of the up-regulated genes were involved in carbohydrate metabolism, amino acid transport & metabolism, and the most down-regulated genes were related to post-translational modification, lipid transport & metabolism, etc. The observed transcriptomic regulation of genes and pathways identified that Enterobacter reduced its post-translational modification, lipid transport & metabolism, and increased carbohydrate metabolism, amino acid metabolism & transport, energy production & conversion to adapt and grow in acidic stress. CONCLUSIONS The present work provides in-depth information on the characterization of genes associated with tolerance or adaptation to acidic stress of Enterobacter bacterium.
Collapse
Affiliation(s)
- Kiran Kumari
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India
| | - Parva Kumar Sharma
- Department of Plant Sciences and Landscape Architecture, University of Maryland, College Park, MD, 20742, USA
| | - Rajnish Prakash Singh
- Department of Biotechnlogy, Jaypee Insttute of Information Technology, Noida, 201309, India.
| |
Collapse
|
2
|
Wang Z, Li N, Xu Y, Wang W, Liu Y. Functional activity of endophytic bacteria G9H01 with high salt tolerance and anti-Magnaporthe oryzae that isolated from saline-alkali-tolerant rice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171822. [PMID: 38521266 DOI: 10.1016/j.scitotenv.2024.171822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/24/2024] [Accepted: 03/17/2024] [Indexed: 03/25/2024]
Abstract
It holds significant practical importance to screen and investigate endophytic bacteria with salt-tolerant activity in rice for the development of relevant microbial agents. A total of 179 strains of endophytic bacteria were isolated from 24 samples of salt-tolerant rice seeds, with almost 95 % of these bacteria exhibiting tolerance to a salt content of 2 % (0.34 mol/L). Following the screening process, a bacterium named G9H01 was identified, which demonstrated a salt tolerance of up to 15 % (2.57 mol/L) and resistance to Magnaporthe oryzae, the causal agent of rice blast disease. Phylogenetic analysis confirmed G9H01 as a strain of Bacillus paralicheniformis. The complete genome of G9H01 was sequenced and assembled, revealing a considerable number of genes encoding proteins associated with salt tolerance. Further analysis indicated that G9H01 may alleviate salt stress in a high-salt environment through various mechanisms. These mechanisms include the utilization of proteins such as K+ transporters, antiporters, and Na+/H+ antiporters, which are involved in K+ absorption and Na+ excretion. G9H01 also demonstrated the ability to uptake and accumulate betaine, as well as secrete extracellular polysaccharides. Collectively, these findings suggest that Bacillus paralicheniformis G9H01 has potential as a biocontrol agent, capable of promoting rice growth under saline-alkali-tolerant conditions.
Collapse
Affiliation(s)
- Zhishan Wang
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Ni Li
- State Key Laboratory of Hybrid Rice (Hunan Hybrid Rice Research Center), Changsha 410125, China
| | - Youqiang Xu
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing 100048, China.
| | - Weiping Wang
- State Key Laboratory of Hybrid Rice (Hunan Hybrid Rice Research Center), Changsha 410125, China.
| | - Yang Liu
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| |
Collapse
|
3
|
Das BK, Kumar V, Das P, Nayak KK. De novo whole transcriptome analysis of Aeromonas hydrophila isolated from the gut of an infected Labeo rohita. Front Microbiol 2023; 14:1247652. [PMID: 37779727 PMCID: PMC10539578 DOI: 10.3389/fmicb.2023.1247652] [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: 06/26/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
Aeromonas hydrophila is a major generalist bacterial pathogen causing severe infections and mortalities in aquatic animals. Its genome, which was the first to be sequenced from the Aeromonas genus, may serve as a model for studying pathogenic mechanisms. To explore the pathogen-host fitness mechanism of bacterium, a comprehensive comparative transcriptome ecotype analysis of A. hydrophila isolated from the gut of Labeo rohita during infection was performed. Special characteristics in gene expression, gene ontology terms and expression of pathogenesis-associated genes, including genes encoding secreted proteins, candidate effectors, hydrolases, and proteins involved in secondary metabolite production were revealed. Among the database, 6,533 were gene ontology (GO) annotated, while 1,480 were not allocated in any GO terms. Investigation on GO illustrated that the articulated genes were improved with molecular function, cellular components, and biological processes. Further bioinformatics analysis identified the outer membrane protein genes (ompA, ompts, ompw, omp38, and omp48), cytotoxin, amylase, and lipase genes. Overall, this work allowed to designate, for the first time, a global view on the pathogenicity of Aeromonas hydrophila during infection. Furthermore, the study provides information on the fitness of A. hydrophila, a severe pathogen with a wide host range.
Collapse
Affiliation(s)
- Basanta Kumar Das
- Aquatic Environmental Biotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
| | - Vikash Kumar
- Aquatic Environmental Biotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
| | - Priyanka Das
- Aquatic Environmental Biotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
| | - Kausalya K. Nayak
- Department of Zoology, K.B.D.A.V. College, Nirakarpur, Odisha, India
| |
Collapse
|
4
|
Rungraeng N, Ohtaguchi K, Chysirichote T. Removal of Histamine from Fish Sauce by Staphylococcus debuckii sp. Isolated from Fermented Fish. Food Technol Biotechnol 2023; 61:294-301. [PMID: 38022886 PMCID: PMC10666945 DOI: 10.17113/ftb.61.03.23.7984] [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: 11/04/2022] [Accepted: 07/05/2023] [Indexed: 12/01/2023] Open
Abstract
Research background One of the issues in the production of fish sauce is the legal constraints on the concentration of histamine produced by bacteria during fermentation because it causes allergic reactions in humans. The goal of this study is therefore to eliminate histamine from the final product after fermentation to enhance the quality of fish sauce for consumer safety, manufacturer exportability and domestic sales. Experimental approach The bacteria that grow in the histamine medium were isolated from the salted fish. Their ability to degrade histamine in the media with high NaCl content was tested. The bacterium with the highest histamine-degrading ability was identified and the histamine-degrading conditions were optimized, including the incubation temperature and the amount of NaCl in the medium. The regression equation was generated and tested using the local fish sauce in which different concentrations of histamine were added. Results and conclusions Among the five bacteria isolated from the salted fish, the isolate with the greatest ability to degrade histamine was identified as Staphylococcus debuckii sp. The study of the capacity of the isolated bacteria to degrade histamine using the synthetic histamine broth (pH=7.0, t=25 °C and NaCl 25 % (m/V)) indicated that they were able to degrade up to 56 % of histamine. The optimization analysis showed that increasing the pH of the medium to 7.5 and lowering the incubation temperature to 20 °C could improve the histamine removal from 56 to 73 %. The generated regression model, validated by the experimental results of histamine removal from fish sauce, showed an acceptable error (not more than 10 %). S. debuckii, the isolated histamine-degrading bacteria, could be used as an inoculum to reduce histamine accumulated in fish products. Novelty and scientific contribution The microbiological technique developed here can decrease the histamine concentration in the final product, fish sauce, to improve its quality in terms of food safety and satisfy the histamine regulation requirement. The findings of this study can also be used to treat other liquid foods that contain high concentrations of histamine.
Collapse
Affiliation(s)
- Natthakan Rungraeng
- Unit of Food Packaging and Biomaterials, School of Agro-Industry, Mae Fah Luang University, Muang, 57100 Chiang Rai, Thailand
| | - Kazuhisa Ohtaguchi
- Department of Chemical Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, 152-8550 Tokyo, Japan
| | - Teerin Chysirichote
- Department of Food Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Ladkrabang, 10520 Bangkok, Thailand
| |
Collapse
|
5
|
Feng Q, Cao S, Liao S, Wassie M, Sun X, Chen L, Xie Y. Fusarium equiseti-inoculation altered rhizosphere soil microbial community, potentially driving perennial ryegrass growth and salt tolerance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:162153. [PMID: 36764552 DOI: 10.1016/j.scitotenv.2023.162153] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Fusarium equiseti is an effective plant growth-promoting fungi that induce systemic disease resistance in plants. However, the role of F. equiseti in regulating salt stress response and the underlying mechanisms remain largely unknown. Here, we investigated the effect of F. equiseti Z7 strain on the growth and salt stress response in perennial ryegrass. Additionally, the role of Z7 in regulating the abundance, composition, and structure of native microbial communities in the rhizosphere soil was determined. We observed that Z7 could produce indole-3-acetic acid (IAA) and siderophores. Hence, Z7 inoculation further enhanced plant growth and salt tolerance in perennial ryegrass. Inoculating Z7 increased K+ and decreased Na+ in plant tissues. Z7 inoculation also enhanced soil quality by reducing soluble salt and increasing available phosphorus. Moreover, inoculating Z7 altered the compositions of bacterial and fungal communities in the rhizosphere soil. For instance, beneficial bacterial genera, such as Flavobacterium, Enterobacter, Agrobacterium, and Burkholderiales were dominantly enriched in Z7-inoculated soil. Interestingly, the relative abundance of these genera showed significantly positive correlations with the fresh weight of perennial ryegrass. Our results demonstrate that Z7 could remarkably promote plant growth and salt tolerance by regulating ion homeostasis in plant tissues and microbial communities in the rhizosphere soil. This study provides a scientific foundation for applying microbes to improve plant growth under extreme salt stress conditions.
Collapse
Affiliation(s)
- Qijia Feng
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China; School of Life Science, University of Chinese Academy of Sciences, Beijing, China.
| | - Shilong Cao
- Department of Pratacultural Sciences, College of Agronomy, Hunan Agricultural University, Changsha 410128, China
| | - Shujie Liao
- Department of Pratacultural Sciences, College of Agronomy, Hunan Agricultural University, Changsha 410128, China
| | - Misganaw Wassie
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China; School of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyan Sun
- Jiangxi Engineering and Technology Research Center for Ecological Remediation of Heavy Metal Pollution, Institute of Microbe, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Liang Chen
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China.
| | - Yan Xie
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China.
| |
Collapse
|
6
|
Heng S, Sutheeworapong S, Champreda V, Uke A, Kosugi A, Pason P, Waeonukul R, Ceballos RM, Ratanakhanokchai K, Tachaapaikoon C. Genomics and cellulolytic, hemicellulolytic, and amylolytic potential of Iocasia fonsfrigidae strain SP3-1 for polysaccharide degradation. PeerJ 2022; 10:e14211. [PMID: 36281362 PMCID: PMC9587714 DOI: 10.7717/peerj.14211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 09/19/2022] [Indexed: 01/24/2023] Open
Abstract
Background Cellulolytic, hemicellulolytic, and amylolytic (CHA) enzyme-producing halophiles are understudied. The recently defined taxon Iocasia fonsfrigidae consists of one well-described anaerobic bacterial strain: NS-1T. Prior to characterization of strain NS-1T, an isolate designated Halocella sp. SP3-1 was isolated and its genome was published. Based on physiological and genetic comparisons, it was suggested that Halocella sp. SP3-1 may be another isolate of I. fronsfrigidae. Despite being geographic variants of the same species, data indicate that strain SP3-1 exhibits genetic, genomic, and physiological characteristics that distinguish it from strain NS-1T. In this study, we examine the halophilic and alkaliphilic nature of strain SP3-1 and the genetic substrates underlying phenotypic differences between strains SP3-1 and NS-1T with focus on sugar metabolism and CHA enzyme expression. Methods Standard methods in anaerobic cell culture were used to grow strains SP3-1 as well as other comparator species. Morphological characterization was done via electron microscopy and Schaeffer-Fulton staining. Data for sequence comparisons (e.g., 16S rRNA) were retrieved via BLAST and EzBioCloud. Alignments and phylogenetic trees were generated via CLUTAL_X and neighbor joining functions in MEGA (version 11). Genomes were assembled/annotated via the Prokka annotation pipeline. Clusters of Orthologous Groups (COGs) were defined by eegNOG 4.5. DNA-DNA hybridization calculations were performed by the ANI Calculator web service. Results Cells of strain SP3-1 are rods. SP3-1 cells grow at NaCl concentrations of 5-30% (w/v). Optimal growth occurs at 37 °C, pH 8.0, and 20% NaCl (w/v). Although phylogenetic analysis based on 16S rRNA gene indicates that strain SP3-1 belongs to the genus Iocasia with 99.58% average nucleotide sequence identity to Iocasia fonsfrigida NS-1T, strain SP3-1 is uniquely an extreme haloalkaliphile. Moreover, strain SP3-1 ferments D-glucose to acetate, butyrate, carbon dioxide, hydrogen, ethanol, and butanol and will grow on L-arabinose, D-fructose, D-galactose, D-glucose, D-mannose, D-raffinose, D-xylose, cellobiose, lactose, maltose, sucrose, starch, xylan and phosphoric acid swollen cellulose (PASC). D-rhamnose, alginate, and lignin do not serve as suitable culture substrates for strain SP3-1. Thus, the carbon utilization profile of strain SP3-1 differs from that of I. fronsfrigidae strain NS-1T. Differences between these two strains are also noted in their lipid composition. Genomic data reveal key differences between the genetic profiles of strain SP3-1 and NS-1T that likely account for differences in morphology, sugar metabolism, and CHA-enzyme potential. Important to this study, I. fonsfrigidae SP3-1 produces and extracellularly secretes CHA enzymes at different levels and composition than type strain NS-1T. The high salt tolerance and pH range of SP3-1 makes it an ideal candidate for salt and pH tolerant enzyme discovery.
Collapse
Affiliation(s)
- Sobroney Heng
- School of Bioresources and Technology, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| | - Sawannee Sutheeworapong
- Pilot Plant Development and Training Institute, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| | - Verawat Champreda
- National Center for Genetic Engineering and Biotechnology, Thailand Science Park, Klong Luang, Pathumthani, Thailand
| | - Ayaka Uke
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences, Ibaraki, Japan
| | - Akihiko Kosugi
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences, Ibaraki, Japan
| | - Patthra Pason
- School of Bioresources and Technology, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| | - Rattiya Waeonukul
- School of Bioresources and Technology, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| | - Ruben Michael Ceballos
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, United States of America,Arkansas Center for Space & Planetary Sciences, University of Arkansas, Fayetteville, AR, United States of America
| | - Khanok Ratanakhanokchai
- School of Bioresources and Technology, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| | - Chakrit Tachaapaikoon
- School of Bioresources and Technology, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut’s Institute of Technology Thonburi, Bangkok, Thailand
| |
Collapse
|
7
|
Kaur C, Gupta M, Garai S, Mishra SK, Chauhan PS, Sopory S, Singla-Pareek SL, Adlakha N, Pareek A. Microbial methylglyoxal metabolism contributes towards growth promotion and stress tolerance in plants. Environ Microbiol 2021; 24:2817-2836. [PMID: 34435423 DOI: 10.1111/1462-2920.15743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 08/16/2021] [Accepted: 08/23/2021] [Indexed: 12/13/2022]
Abstract
Plant growth promotion by microbes is a cumulative phenomenon involving multiple traits, many of which are not explored yet. Hence, to unravel microbial mechanisms underlying growth promotion, we have analysed the genomes of two potential growth-promoting microbes, viz., Pseudomonas sp. CK-NBRI-02 (P2) and Bacillus marisflavi CK-NBRI-03 (P3) for the presence of plant-beneficial traits. Besides known traits, we found that microbes differ in their ability to metabolize methylglyoxal (MG), a ubiquitous cytotoxin regarded as general consequence of stress in plants. P2 exhibited greater tolerance to MG and possessed better ability to sustain plant growth under dicarbonyl stress. However, under salinity, only P3 showed a dose-dependent induction in MG detoxification activity in accordance with concomitant increase in MG levels, contributing to enhanced salt tolerance. Furthermore, salt-stressed transcriptomes of both the strains showed differences with respect to MG, ion and osmolyte homeostasis, with P3 being more responsive to stress. Importantly, application of either strain altered MG levels and subsequently MG detoxification machinery in Arabidopsis, probably to strengthen plant defence response and growth. We therefore, suggest a crucial role of microbial MG resistance in plant growth promotion and that it should be considered as a beneficial trait while screening microbes for stress mitigation in plants.
Collapse
Affiliation(s)
- Charanpreet Kaur
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.,International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Mayank Gupta
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Sampurna Garai
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Shashank K Mishra
- Microbial Technologies Division, CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh, India
| | - Puneet Singh Chauhan
- Microbial Technologies Division, CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh, India
| | - Sudhir Sopory
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Sneh L Singla-Pareek
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Nidhi Adlakha
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, 121001, India
| | - Ashwani Pareek
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| |
Collapse
|
8
|
Sunita K, Mishra I, Mishra J, Prakash J, Arora NK. Secondary Metabolites From Halotolerant Plant Growth Promoting Rhizobacteria for Ameliorating Salinity Stress in Plants. Front Microbiol 2020; 11:567768. [PMID: 33193157 PMCID: PMC7641974 DOI: 10.3389/fmicb.2020.567768] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/29/2020] [Indexed: 12/23/2022] Open
Abstract
Soil salinization has emerged as one of the prime environmental constraints endangering soil quality and agricultural productivity. Anthropogenic activities coupled with rapid pace of climate change are the key drivers of soil salinity resulting in degradation of agricultural lands. Increasing levels of salt not only impair structure of soil and its microbial activity but also restrict plant growth by causing harmful imbalance and metabolic disorders. Potential of secondary metabolites synthesized by halotolerant plant growth promoting rhizobacteria (HT-PGPR) in the management of salinity stress in crops is gaining importance. A wide array of secondary metabolites such as osmoprotectants/compatible solutes, exopolysaccharides (EPS) and volatile organic compounds (VOCs) from HT-PGPR have been reported to play crucial roles in ameliorating salinity stress in plants and their symbiotic partners. In addition, HT-PGPR and their metabolites also help in prompt buffering of the salt stress and act as biological engineers enhancing the quality and productivity of saline soils. The review documents prominent secondary metabolites from HT-PGPR and their role in modulating responses of plants to salinity stress. The review also highlights the mechanisms involved in the production of secondary metabolites by HT-PGPR in saline conditions. Utilizing the HT-PGPR and their secondary metabolites for the development of novel bioinoculants for the management of saline agro-ecosystems can be an important strategy in the future.
Collapse
Affiliation(s)
- Kumari Sunita
- Department of Botany, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, India
| | - Isha Mishra
- Department of Microbiology, School for Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Jitendra Mishra
- DST-Center for Policy Research, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Jai Prakash
- Department of Microbiology, School for Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Naveen Kumar Arora
- Department of Environmental Science, School for Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| |
Collapse
|