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Thompson MEH, Raizada MN. The Microbiome of Fertilization-Stage Maize Silks (Style) Encodes Genes and Expresses Traits That Potentially Promote Survival in Pollen/Style Niches and Host Reproduction. Microorganisms 2024; 12:1473. [PMID: 39065240 DOI: 10.3390/microorganisms12071473] [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: 06/27/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Within flowers, the style channel receives pollen and transmits male gametes inside elongating pollen tubes to ovules. The styles of maize/corn are called silks. Fertilization-stage silks possess complex microbiomes, which may partially derive from pollen. These microbiomes lack functional analysis. We hypothesize that fertilization-stage silk microbiomes promote host fertilization to ensure their own vertical transmission. We further hypothesize that these microbes encode traits to survive stresses within the silk (water/nitrogen limitation) and pollen (dehydration/aluminum) habitats. Here, bacteria cultured from fertilization-stage silks of 14 North American maize genotypes underwent genome mining and functional testing, which revealed osmoprotection, nitrogen-fixation, and aluminum-tolerance traits. Bacteria contained auxin biosynthesis genes, and testing confirmed indole compound secretion, which is relevant, since pollen delivers auxin to silks to stimulate egg cell maturation. Some isolates encoded biosynthetic/transport compounds known to regulate pollen tube guidance/growth. The isolates encoded ACC deaminase, which degrades the precursor for ethylene that otherwise accelerates silk senescence. The findings suggest that members of the microbiome of fertilization-stage silks encode adaptations to survive the stress conditions of silk/pollen and have the potential to express signaling compounds known to impact reproduction. Overall, whereas these microbial traits have traditionally been assumed to primarily promote vegetative plant growth, this study proposes they may also play selfish roles during host reproduction.
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Affiliation(s)
| | - Manish N Raizada
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
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2
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Chowardhara B, Saha B, Awasthi JP, Deori BB, Nath R, Roy S, Sarkar S, Santra SC, Hossain A, Moulick D. An assessment of nanotechnology-based interventions for cleaning up toxic heavy metal/metalloid-contaminated agroecosystems: Potentials and issues. CHEMOSPHERE 2024; 359:142178. [PMID: 38704049 DOI: 10.1016/j.chemosphere.2024.142178] [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: 08/22/2023] [Revised: 03/22/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
Heavy metals (HMs) are among the most dangerous environmental variables for a variety of life forms, including crops. Accumulation of HMs in consumables and their subsequent transmission to the food web are serious concerns for scientific communities and policy makers. The function of essential plant cellular macromolecules is substantially hampered by HMs, which eventually have a detrimental effect on agricultural yield. Among these HMs, three were considered, i.e., arsenic, cadmium, and chromium, in this review, from agro-ecosystem perspective. Compared with conventional plant growth regulators, the use of nanoparticles (NPs) is a relatively recent, successful, and promising method among the many methods employed to address or alleviate the toxicity of HMs. The ability of NPs to reduce HM mobility in soil, reduce HM availability, enhance the ability of the apoplastic barrier to prevent HM translocation inside the plant, strengthen the plant's antioxidant system by significantly enhancing the activities of many enzymatic and nonenzymatic antioxidants, and increase the generation of specialized metabolites together support the effectiveness of NPs as stress relievers. In this review article, to assess the efficacy of various NP types in ameliorating HM toxicity in plants, we adopted a 'fusion approach', in which a machine learning-based analysis was used to systematically highlight current research trends based on which an extensive literature survey is planned. A holistic assessment of HMs and NMs was subsequently carried out to highlight the future course of action(s).
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Affiliation(s)
- Bhaben Chowardhara
- Department of Botany, Faculty of Science and Technology, Arunachal University of Studies, Namsai, Arunachal Pradesh-792103, India.
| | - Bedabrata Saha
- Plant Pathology and Weed Research Department, Newe Ya'ar Research Centre, Agricultural Research Organization, Ramat Yishay-3009500, Israel.
| | - Jay Prakash Awasthi
- Department of Botany, Government College Lamta, Balaghat, Madhya Pradesh 481551, India.
| | - Biswajit Bikom Deori
- Department of Environmental Science, Faculty of Science and Technology, Arunachal University of Studies, Namsai, Arunachal Pradesh 792103, India.
| | - Ratul Nath
- Department of Life-Science, Dibrugarh University, Dibrugarh, Assam-786004, India.
| | - Swarnendu Roy
- Department of Botany, University of North Bengal, P.O.- NBU, Dist- Darjeeling, West Bengal, 734013, India.
| | - Sukamal Sarkar
- Division of Agronomy, School of Agriculture and Rural Development, Ramakrishna Mission Vivekananda Educational and Research Institute, Narendrapur Campus, Kolkata, India.
| | - Subhas Chandra Santra
- Department of Environmental Science, University of Kalyani, Nadia, West Bengal, 741235, India.
| | - Akbar Hossain
- Division of Soil Science, Bangladesh Wheat and Maize Research Institute, Dinajpur 5200, Bangladesh.
| | - Debojyoti Moulick
- Department of Environmental Science, University of Kalyani, Nadia, West Bengal, 741235, India.
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Shrestha A, Limay-Rios V, Brettingham DJL, Raizada MN. Maize pollen carry bacteria that suppress a fungal pathogen that enters through the male gamete fertilization route. FRONTIERS IN PLANT SCIENCE 2024; 14:1286199. [PMID: 38269134 PMCID: PMC10806238 DOI: 10.3389/fpls.2023.1286199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024]
Abstract
In flowering plants, after being released from pollen grains, the male gametes use the style channel to migrate towards the ovary where they fertilize awaiting eggs. Environmental pathogens exploit the style passage, resulting in diseased progeny seed. The belief is that pollen also transmits pathogens into the style. By contrast, we hypothesized that pollen carries beneficial microbes that suppress environmental pathogens on the style passage. No prior studies have reported pollen-associated bacterial functions in any plant species. Here, bacteria were cultured from maize (corn) pollen encompassing wild ancestors and farmer-selected landraces from across the Americas, grown in a common field in Canada for one season. In total, 298 bacterial isolates were cultured, spanning 45 genera, 103 species, and 88 OTUs, dominated by Pantoea, Bacillus, Pseudomonas, Erwinia, and Microbacterium. Full-length 16S DNA-based taxonomic profiling showed that 78% of bacterial taxa from the major wild ancestor of maize (Parviglumis teosinte) were present in at least one cultivated landrace. The species names of the bacterial isolates were used to search the pathogen literature systematically; this preliminary evidence predicted that the vast majority of the pollen-associated bacteria analyzed are not maize pathogens. The pollen-associated bacteria were tested in vitro against a style-invading Fusarium pathogen shown to cause Gibberella ear rot (GER): 14 isolates inhibited this pathogen. Genome mining showed that all the anti-Fusarium bacterial species encode phzF, associated with biosynthesis of the natural fungicide, phenazine. To mimic the male gamete migration route, three pollen-associated bacterial strains were sprayed onto styles (silks), followed by Fusarium inoculation; these bacteria reduced GER symptoms and mycotoxin accumulation in progeny seed. Confocal microscopy was used to search for direct evidence that pollen-associated bacteria can defend living silks against Fusarium graminearum (Fg); bacterial strain AS541 (Kluyvera intermedia), isolated from pollen of ancestral Parviglumis, was observed to colonize the susceptible style/silk entry points of Fg (silk epidermis, trichomes, wounds). Furthermore, on style/silk tissue, AS541 colonized/aggregated on Fg hyphae, and was associated with Fg hyphal breaks. These results suggest that pollen has the potential to carry bacteria that can defend the style/silk passage against an environmental pathogen - a novel observation.
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Affiliation(s)
- Anuja Shrestha
- Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - Victor Limay-Rios
- Department of Plant Agriculture, University of Guelph, Ridgetown, ON, Canada
| | | | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
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Goswami SK, Kashyap AS, Kumar R, Gujjar RS, Singh A, Manzar N. Harnessing Rhizospheric Microbes for Eco-friendly and Sustainable Crop Production in Saline Environments. Curr Microbiol 2023; 81:14. [PMID: 38006515 DOI: 10.1007/s00284-023-03538-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/24/2023] [Indexed: 11/27/2023]
Abstract
Soil salinization is a global issue that negatively impacts crop yield and has become a prime concern for researchers worldwide. Many important crop plants are susceptible to salinity-induced stresses, including ionic and osmotic stress. Approximately, 20% of the world's cultivated and 33% of irrigated land is affected by salt. While various agricultural practices have been successful in alleviating salinity stress, they can be costly and not environment-friendly. Therefore, there is a need for cost-effective and eco-friendly practices to improve soil health. One promising approach involves utilizing microbes found in the vicinity of plant roots to mitigate the effects of salinity stress and enhance plant growth as well as crop yield. By exploiting the salinity tolerance of plants and their associated rhizospheric microorganisms, which have plant growth-promoting properties, it is possible to reduce the adverse effects of salt stress on crop plants. The soil salinization is a common problem in the world, due to which we are unable to use the saline land. To make proper use of this land for different crops, microorganisms can play an important role. Looking at the increasing population of the world, this will be an appreciated effort to make the best use of the wasted land for food security. The updated information on this issue is needed. In this context, this article provides a concise review of the latest research on the use of salt-tolerant rhizospheric microorganisms to mitigate salinity stress in crop plants.
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Affiliation(s)
- Sanjay K Goswami
- ICAR-Indian Institute of Sugarcane Research, Rai Bareli Road, Dilkusha, Lucknow, Uttar Pradesh, 220026, India
| | - Abhijeet S Kashyap
- ICAR-National Bureau of Agriculturally Important Microorganism, Mau, 275103, India
| | - Rajeev Kumar
- ICAR-Indian Institute of Sugarcane Research, Rai Bareli Road, Dilkusha, Lucknow, Uttar Pradesh, 220026, India
| | - Ranjit Singh Gujjar
- ICAR-Indian Institute of Sugarcane Research, Rai Bareli Road, Dilkusha, Lucknow, Uttar Pradesh, 220026, India.
| | - Arjun Singh
- ICAR-CSSRI Regional Research Station, Rai Bareli Road, Dilkusha, Lucknow, Uttar Pradesh, 220026, India
| | - Nazia Manzar
- ICAR-National Bureau of Agriculturally Important Microorganism, Mau, 275103, India
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Xia Y, Yuan Y, Li C, Sun Z. Phosphorus-solubilizing bacteria improve the growth of Nicotiana benthamiana on lunar regolith simulant by dissociating insoluble inorganic phosphorus. Commun Biol 2023; 6:1039. [PMID: 37945659 PMCID: PMC10636133 DOI: 10.1038/s42003-023-05391-z] [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: 04/18/2023] [Accepted: 09/26/2023] [Indexed: 11/12/2023] Open
Abstract
In-situ utilization of lunar soil resources will effectively improve the self-sufficiency of bioregenerative life support systems for future lunar bases. Therefore, we have explored the microbiological method to transform lunar soil into a substrate for plant cultivation. In this study, five species of phosphorus-solubilizing bacteria are used as test strains, and a 21-day bio-improving experiment with another 24-day Nicotiana benthamiana cultivation experiment are carried out on lunar regolith simulant. We have observed that the phosphorus-solublizing bacteria Bacillus mucilaginosus, Bacillus megaterium, and Pseudomonas fluorescens can tolerate the lunar regolith simulant conditions and dissociate the insoluble phosphorus from the regolith simulant. The phosphorus-solubilizing bacteria treatment improves the available phosphorus content of the regolith simulant, promoting the growth of Nicotiana benthamiana. Here we demonstrate that the phosphorus-solubilizing bacteria can effectively improve the fertility of lunar regolith simulant, making it a good cultivation substrate for higher plants. The results can lay a technical foundation for plant cultivation based on lunar regolith resources in future lunar bases.
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Affiliation(s)
- Yitong Xia
- College of Agronomy and Biotechnology, China Agricultural University, Haidian District, Beijing, China
| | - Yu Yuan
- College of Engineering, China Agricultural University, Haidian District, Beijing, China
| | - Chenxi Li
- College of Horticulture, China Agricultural University, Haidian District, Beijing, China
| | - Zhencai Sun
- College of Agronomy and Biotechnology, China Agricultural University, Haidian District, Beijing, China.
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Thompson MEH, Shrestha A, Rinne J, Limay-Rios V, Reid L, Raizada MN. The Cultured Microbiome of Pollinated Maize Silks Shifts after Infection with Fusarium graminearum and Varies by Distance from the Site of Pathogen Inoculation. Pathogens 2023; 12:1322. [PMID: 38003787 PMCID: PMC10675081 DOI: 10.3390/pathogens12111322] [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: 10/04/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
Styles transmit pollen-derived sperm nuclei from pollen to ovules, but also transmit environmental pathogens. The microbiomes of styles are likely important for reproduction/disease, yet few studies exist. Whether style microbiome compositions are spatially responsive to pathogens is unknown. The maize pathogen Fusarium graminearum enters developing grain through the style (silk). We hypothesized that F. graminearum treatment shifts the cultured transmitting silk microbiome (TSM) compared to healthy silks in a distance-dependent manner. Another objective of the study was to culture microbes for future application. Bacteria were cultured from husk-covered silks of 14 F. graminearum-treated diverse maize genotypes, proximal (tip) and distal (base) to the F. graminearum inoculation site. Long-read 16S sequences from 398 isolates spanned 35 genera, 71 species, and 238 OTUs. More bacteria were cultured from F. graminearum-inoculated tips (271 isolates) versus base (127 isolates); healthy silks were balanced. F. graminearum caused a collapse in diversity of ~20-25% across multiple taxonomic levels. Some species were cultured exclusively or, more often, from F. graminearum-treated silks (e.g., Delftia acidovorans, Klebsiella aerogenes, K. grimontii, Pantoea ananatis, Stenotrophomonas pavanii). Overall, the results suggest that F. graminearum alters the TSM in a distance-dependent manner. Many isolates matched taxa that were previously identified using V4-MiSeq (core and F. graminearum-induced), but long-read sequencing clarified the taxonomy and uncovered greater diversity than was initially predicted (e.g., within Pantoea). These isolates represent the first comprehensive cultured collection from pathogen-treated maize silks to facilitate biocontrol efforts and microbial marker-assisted breeding.
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Affiliation(s)
- Michelle E. H. Thompson
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; (M.E.H.T.)
| | - Anuja Shrestha
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; (M.E.H.T.)
| | - Jeffrey Rinne
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; (M.E.H.T.)
| | - Victor Limay-Rios
- Department of Plant Agriculture, University of Guelph Ridgetown Campus, 120 Main Street E, Ridgetown, ON N0P 2C0, Canada
| | - Lana Reid
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Central Experimental Farm, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada
| | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; (M.E.H.T.)
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De-la-Vega-Camarillo E, Hernández-García JA, Villa-Tanaca L, Hernández-Rodríguez C. Unlocking the hidden potential of Mexican teosinte seeds: revealing plant growth-promoting bacterial and fungal biocontrol agents. FRONTIERS IN PLANT SCIENCE 2023; 14:1247814. [PMID: 37860235 PMCID: PMC10582567 DOI: 10.3389/fpls.2023.1247814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/15/2023] [Indexed: 10/21/2023]
Abstract
The bacterial component of plant holobiont maintains valuable interactions that contribute to plants' growth, adaptation, stress tolerance, and antagonism to some phytopathogens. Teosinte is the grass plant recognized as the progenitor of modern maize, domesticated by pre-Hispanic civilizations around 9,000 years ago. Three teosinte species are recognized: Zea diploperennis, Zea perennis, and Zea mays. In this work, the bacterial diversity of three species of Mexican teosinte seeds was explored by massive sequencing of 16S rRNA amplicons. Streptomyces, Acinetobacter, Olivibacter, Erwinia, Bacillus, Pseudomonas, Cellvibrio, Achromobacter, Devosia, Lysobacter, Sphingopyxis, Stenotrophomonas, Ochrobactrum, Delftia, Lactobacillus, among others, were the bacterial genera mainly represented. The bacterial alpha diversity in the seeds of Z. diploperennis was the highest, while the alpha diversity in Z. mays subsp. mexicana race was the lowest observed among the species and races. The Mexican teosintes analyzed had a core bacteriome of 38 bacterial genera, including several recognized plant growth promoters or fungal biocontrol agents such as Agrobacterium, Burkholderia, Erwinia, Lactobacillus, Ochrobactrum, Paenibacillus, Pseudomonas, Sphingomonas, Streptomyces, among other. Metabolic inference analysis by PICRUSt2 of bacterial genera showed several pathways related to plant growth promotion (PGP), biological control, and environmental adaptation. The implications of these findings are far-reaching, as they highlight the existence of an exceptional bacterial germplasm reservoir teeming with potential plant growth promotion bacteria (PGPB). This reserve holds the key to cultivating innovative bioinoculants and formidable fungal antagonistic strains, thereby paving the way for a more sustainable and eco-friendly approach to agriculture. Embracing these novel NGS-based techniques and understanding the profound impact of the vertical transference of microorganisms from seeds could revolutionize the future of agriculture and develop a new era of symbiotic harmony between plants and microbes.
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Affiliation(s)
| | | | | | - César Hernández-Rodríguez
- Laboratorio de Biología Molecular de Bacterias y Levaduras, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
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Kamran M, Imran QM, Ahmed MB, Falak N, Khatoon A, Yun BW. Endophyte-Mediated Stress Tolerance in Plants: A Sustainable Strategy to Enhance Resilience and Assist Crop Improvement. Cells 2022; 11:cells11203292. [PMID: 36291157 PMCID: PMC9600683 DOI: 10.3390/cells11203292] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 10/09/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Biotic and abiotic stresses severely affect agriculture by affecting crop productivity, soil fertility, and health. These stresses may have significant financial repercussions, necessitating a practical, cost-effective, and ecologically friendly approach to lessen their negative impacts on plants. Several agrochemicals, such as fertilizers, pesticides, and insecticides, are used to improve plant health and protection; however, these chemical supplements have serious implications for human health. Plants being sessile cannot move or escape to avoid stress. Therefore, they have evolved to develop highly beneficial interactions with endophytes. The targeted use of beneficial plant endophytes and their role in combating biotic and abiotic stresses are gaining attention. Therefore, it is important to experimentally validate these interactions and determine how they affect plant fitness. This review highlights research that sheds light on how endophytes help plants tolerate biotic and abiotic stresses through plant–symbiont and plant–microbiota interactions. There is a great need to focus research efforts on this vital area to achieve a system-level understanding of plant–microbe interactions that occur naturally.
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Affiliation(s)
- Muhammad Kamran
- School of Molecular Sciences, The University of Western Australia, M310, 35 Stirling Hwy, Perth, WA 6009, Australia
- Correspondence: (M.K.); (B.-W.Y.)
| | - Qari Muhammad Imran
- Department of Medical Biochemistry & Biophysics, Umea University, 90187 Umea, Sweden
- Laboratory of Plant Molecular Pathology and Functional Genomics, Division of Plant Biosciences, College of Agriculture and & Life Science, Kyungpook National University, Daegu 41566, Korea
| | - Muhammad Bilal Ahmed
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Noreen Falak
- Laboratory of Plant Molecular Pathology and Functional Genomics, Division of Plant Biosciences, College of Agriculture and & Life Science, Kyungpook National University, Daegu 41566, Korea
| | - Amna Khatoon
- Department of Botany, Kohat University of Science and Technology, Kohat 26000, Pakistan
| | - Byung-Wook Yun
- Laboratory of Plant Molecular Pathology and Functional Genomics, Division of Plant Biosciences, College of Agriculture and & Life Science, Kyungpook National University, Daegu 41566, Korea
- Correspondence: (M.K.); (B.-W.Y.)
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Chaudhary P, Singh S, Chaudhary A, Sharma A, Kumar G. Overview of biofertilizers in crop production and stress management for sustainable agriculture. FRONTIERS IN PLANT SCIENCE 2022; 13:930340. [PMID: 36082294 PMCID: PMC9445558 DOI: 10.3389/fpls.2022.930340] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/21/2022] [Indexed: 05/09/2023]
Abstract
With the increase in world population, the demography of humans is estimated to be exceeded and it has become a major challenge to provide an adequate amount of food, feed, and agricultural products majorly in developing countries. The use of chemical fertilizers causes the plant to grow efficiently and rapidly to meet the food demand. The drawbacks of using a higher quantity of chemical or synthetic fertilizers are environmental pollution, persistent changes in the soil ecology, physiochemical composition, decreasing agricultural productivity and cause several health hazards. Climatic factors are responsible for enhancing abiotic stress on crops, resulting in reduced agricultural productivity. There are various types of abiotic and biotic stress factors like soil salinity, drought, wind, improper temperature, heavy metals, waterlogging, and different weeds and phytopathogens like bacteria, viruses, fungi, and nematodes which attack plants, reducing crop productivity and quality. There is a shift toward the use of biofertilizers due to all these facts, which provide nutrition through natural processes like zinc, potassium and phosphorus solubilization, nitrogen fixation, production of hormones, siderophore, various hydrolytic enzymes and protect the plant from different plant pathogens and stress conditions. They provide the nutrition in adequate amount that is sufficient for healthy crop development to fulfill the demand of the increasing population worldwide, eco-friendly and economically convenient. This review will focus on biofertilizers and their mechanisms of action, role in crop productivity and in biotic/abiotic stress tolerance.
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Affiliation(s)
- Parul Chaudhary
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Shivani Singh
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Anuj Chaudhary
- School of Agriculture and Environmental Science, Shobhit University, Gangoh, India
| | - Anita Sharma
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Govind Kumar
- Department of Crop Production, Central Institute for Subtropical Horticulture, Lucknow, India
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Byregowda R, Prasad SR, Oelmüller R, Nataraja KN, Prasanna Kumar MK. Is Endophytic Colonization of Host Plants a Method of Alleviating Drought Stress? Conceptualizing the Hidden World of Endophytes. Int J Mol Sci 2022; 23:ijms23169194. [PMID: 36012460 PMCID: PMC9408852 DOI: 10.3390/ijms23169194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022] Open
Abstract
In the wake of changing climatic conditions, plants are frequently exposed to a wide range of biotic and abiotic stresses at various stages of their development, all of which negatively affect their growth, development, and productivity. Drought is one of the most devastating abiotic stresses for most cultivated crops, particularly in arid and semiarid environments. Conventional breeding and biotechnological approaches are used to generate drought-tolerant crop plants. However, these techniques are costly and time-consuming. Plant-colonizing microbes, notably, endophytic fungi, have received increasing attention in recent years since they can boost plant growth and yield and can strengthen plant responses to abiotic stress. In this review, we describe these microorganisms and their relationship with host plants, summarize the current knowledge on how they “reprogram” the plants to promote their growth, productivity, and drought tolerance, and explain why they are promising agents in modern agriculture.
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Affiliation(s)
- Roopashree Byregowda
- Department of Seed Science and Technology, University of Agricultural Sciences, Bangalore 560065, India
- Department of Plant Physiology, Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich-Schiller-University, 07743 Jena, Germany
| | | | - Ralf Oelmüller
- Department of Plant Physiology, Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich-Schiller-University, 07743 Jena, Germany
- Correspondence:
| | - Karaba N. Nataraja
- Department of Crop Physiology, University of Agricultural Sciences, Bangalore 560065, India
| | - M. K. Prasanna Kumar
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore 560065, India
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11
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Progress and Applications of Plant Growth-Promoting Bacteria in Salt Tolerance of Crops. Int J Mol Sci 2022; 23:ijms23137036. [PMID: 35806037 PMCID: PMC9266936 DOI: 10.3390/ijms23137036] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/04/2023] Open
Abstract
Saline soils are a major challenge in agriculture, and salinization is increasing worldwide due to climate change and destructive agricultural practices. Excessive amounts of salt in soils cause imbalances in ion distribution, physiological dehydration, and oxidative stress in plants. Breeding and genetic engineering methods to improve plant salt tolerance and the better use of saline soils are being explored; however, these approaches can take decades to accomplish. A shorter-term approach to improve plant salt tolerance is to be inoculated with bacteria with high salt tolerance or adjusting the balance of bacteria in the rhizosphere, including endosymbiotic bacteria (living in roots or forming a symbiont) and exosymbiotic bacteria (living on roots). Rhizosphere bacteria promote plant growth and alleviate salt stress by providing minerals (such as nitrogen, phosphate, and potassium) and hormones (including auxin, cytokinin, and abscisic acid) or by reducing ethylene production. Plant growth-promoting rhizosphere bacteria are a promising tool to restore agricultural lands and improve plant growth in saline soils. In this review, we summarize the mechanisms of plant growth-promoting bacteria under salt stress and their applications for improving plant salt tolerance to provide a theoretical basis for further use in agricultural systems.
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12
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Biologicals and their plant stress tolerance ability. Symbiosis 2022. [DOI: 10.1007/s13199-022-00842-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Castillo JA, Conde G, Claros M, Ortuño N. Diversity of cultivable microorganisms associated with Quinoa (Chenopodium quinoa) and their potential for plant growth-promotion. BIONATURA 2022. [DOI: 10.21931/rb/2022.07.02.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Quinoa (Chenopodium quinoa) has grown since ancestral times in the Andean mountains and Altiplano, which are the center of origin of this pseudo-cereal. The interaction of Quinoa with native microorganisms may have contributed to the success of this plant in very adverse climatic and soil conditions. This study addressed the microbial diversity associated with Quinoa plants growing in traditional lands. We employed a cultivable-dependent approach to characterize the communities and identify bacterial strains with potential application in agriculture. We identified bacterial isolates belonging to phyla Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria. The genera Bacillus and Rhizobium/Agrobacterium were the predominant groups in the Quinoa bacterial communities, while various Trichoderma species were also found in the fungi group. The plant growth-promoting ability of selected bacterial strains was assessed by culturing them on media and the in planta test. We used different assays to test the capabilities of the isolates for nitrogen fixation, phosphorus solubilization, and production of the phytohormone indole-3-acetic acid. We inoculated Quinoa seeds with some Bacillus strains and then evaluated plant growth and grain production. Plants inoculated with bacterial strains usually show increased growth parameters and grain yield. Altogether, this work reveals that Quinoa harbors many diverse cultivable bacteria and fungi, which could be used as biological amendments to promote plant growth in a chemical-free way. Avoiding chemical fertilizers helps reduce environmental pollution and maintains the organic character of Quinoa production. International Quinoa markets highly appreciate the organic quality of Quinoa.
Keywords. Plant growth-promoting bacteria, Microbial diversity, Rhizosphere bacteria, Andean Altiplano, Trichoderma
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Affiliation(s)
- José A. Castillo
- Fundación PROINPA, Av. Meneces Km. 4, El Paso, Cochabamba, Bolivia. 2 School of Biological Sciences and Engineering, Yachay Tech University, San Miguel de Urcuquí, Imbabura, Ecuador
| | | | - Mayra Claros
- Faculty of Agricultural and Livestock Sciences, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Noel Ortuño
- Faculty of Agricultural and Livestock Sciences, Universidad Mayor de San Simón, Cochabamba, Bolivia
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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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15
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Sahu PK, Tilgam J, Mishra S, Hamid S, Gupta A, K J, Verma SK, Kharwar RN. Surface sterilization for isolation of endophytes: Ensuring what (not) to grow. J Basic Microbiol 2022; 62:647-668. [PMID: 35020220 DOI: 10.1002/jobm.202100462] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/29/2021] [Accepted: 12/31/2021] [Indexed: 12/19/2022]
Abstract
Endophytic microbiota opens a magnificent arena of metabolites that served as a potential source of medicines for treating a variety of ailments and having prospective uses in agriculture, food, cosmetics, and many more. There are umpteen reports of endophytes improving the growth and tolerance of plants. In addition, endophytes from lifesaving drug-producing plants such as Taxus, Nothapodytes, Catharanthus, and so forth have the ability to produce host mimicking compounds. To harness these benefits, it is imperative to isolate the true endophytes, not the surface microflora. The foremost step in endophyte isolation is the removal of epiphytic microbes from plant tissues, called as surface sterilization. The success of surface sterilization decides "what to grow" (the endophytes) and "what not to grow" (the epiphytes). It is very crucial to use an appropriate sterilant solution, concentration, and exposure time to ensure thorough surface disinfection with minimal damage to the endophytic diversity. Commonly used surface sterilants include sodium hypochlorite (2%-10%), ethanol (70%-90%), mercuric chloride (0.1%), formaldehyde (40%), and so forth. In addition, the efficiency could further be improved by pretreatment with surfactants such as Triton X-100, Tween 80, and Tween 20. This review comprehensively deals with the various sterilants and sterilization methods for the isolation of endophytic microbes. In addition, the mechanisms and rationale behind using specific surface sterilants have also been elaborated at length.
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Affiliation(s)
- Pramod K Sahu
- ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan, Uttar Pradesh, India
| | - Jyotsana Tilgam
- ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan, Uttar Pradesh, India
| | - Sushma Mishra
- Plant Biotechnology Laboratory, Dayalbagh Educational Institute (Deemed-to-be-University), Agra, Uttar Pradesh, India
| | - Saima Hamid
- Department of Plant Biotechnology and Microbial Ecology, University of Kashmir, Hazratbal, Srinagar, Jammu & Kashmir, India
| | - Amrita Gupta
- Department of Biotechnology, Amity Institute of Biotechnology, Amity University, Lucknow, Uttar Pradesh, India
| | - Jayalakshmi K
- ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan, Uttar Pradesh, India
| | - Satish K Verma
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Ravindra N Kharwar
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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Jiménez-Mejía R, Medina-Estrada RI, Carballar-Hernández S, Orozco-Mosqueda MDC, Santoyo G, Loeza-Lara PD. Teamwork to Survive in Hostile Soils: Use of Plant Growth-Promoting Bacteria to Ameliorate Soil Salinity Stress in Crops. Microorganisms 2022; 10:150. [PMID: 35056599 PMCID: PMC8781547 DOI: 10.3390/microorganisms10010150] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/30/2022] Open
Abstract
Plants and their microbiomes, including plant growth-promoting bacteria (PGPB), can work as a team to reduce the adverse effects of different types of stress, including drought, heat, cold, and heavy metals stresses, as well as salinity in soils. These abiotic stresses are reviewed here, with an emphasis on salinity and its negative consequences on crops, due to their wide presence in cultivable soils around the world. Likewise, the factors that stimulate the salinity of soils and their impact on microbial diversity and plant physiology were also analyzed. In addition, the saline soils that exist in Mexico were analyzed as a case study. We also made some proposals for a more extensive use of bacterial bioinoculants in agriculture, particularly in developing countries. Finally, PGPB are highly relevant and extremely helpful in counteracting the toxic effects of soil salinity and improving crop growth and production; therefore, their use should be intensively promoted.
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Affiliation(s)
- Rafael Jiménez-Mejía
- Licenciatura en Genómica Alimentaria, Universidad de La Ciénega del Estado de Michoacán de Ocampo (UCEMICH), Sahuayo 59103, Mexico; (R.J.-M.); (R.I.M.-E.); (S.C.-H.)
| | - Ricardo I. Medina-Estrada
- Licenciatura en Genómica Alimentaria, Universidad de La Ciénega del Estado de Michoacán de Ocampo (UCEMICH), Sahuayo 59103, Mexico; (R.J.-M.); (R.I.M.-E.); (S.C.-H.)
| | - Santos Carballar-Hernández
- Licenciatura en Genómica Alimentaria, Universidad de La Ciénega del Estado de Michoacán de Ocampo (UCEMICH), Sahuayo 59103, Mexico; (R.J.-M.); (R.I.M.-E.); (S.C.-H.)
| | - Ma. del Carmen Orozco-Mosqueda
- Facultad de Agrobiología “Presidente Juárez”, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Uruapan 60170, Mexico;
| | - Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia 58030, Mexico;
| | - Pedro D. Loeza-Lara
- Licenciatura en Genómica Alimentaria, Universidad de La Ciénega del Estado de Michoacán de Ocampo (UCEMICH), Sahuayo 59103, Mexico; (R.J.-M.); (R.I.M.-E.); (S.C.-H.)
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Roy S, Chakraborty AP, Chakraborty R. Understanding the potential of root microbiome influencing salt-tolerance in plants and mechanisms involved at the transcriptional and translational level. PHYSIOLOGIA PLANTARUM 2021; 173:1657-1681. [PMID: 34549441 DOI: 10.1111/ppl.13570] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/10/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Soil salinity severely affects plant growth and development and imparts inevitable losses to crop productivity. Increasing the concentration of salts in the vicinity of plant roots has severe consequences at the morphological, biochemical, and molecular levels. These include loss of chlorophyll, decrease in photosynthetic rate, reduction in cell division, ROS generation, inactivation of antioxidative enzymes, alterations in phytohormone biosynthesis and signaling, and so forth. The association of microorganisms, viz. plant growth-promoting rhizobacteria, endophytes, and mycorrhiza, with plant roots constituting the root microbiome can confer a greater degree of salinity tolerance in addition to their inherent ability to promote growth and induce defense mechanisms. The mechanisms involved in induced stress tolerance bestowed by these microorganisms involve the modulation of phytohormone biosynthesis and signaling pathways (including indole acetic acid, gibberellic acid, brassinosteroids, abscisic acid, and jasmonic acid), accumulation of osmoprotectants (proline, glycine betaine, and sugar alcohols), and regulation of ion transporters (SOS1, NHX, HKT1). Apart from this, salt-tolerant microorganisms are known to induce the expression of salt-responsive genes via the action of several transcription factors, as well as by posttranscriptional and posttranslational modifications. Moreover, the potential of these salt-tolerant microflora can be employed for sustainably improving crop performance in saline environments. Therefore, this review will briefly focus on the key responses of plants under salinity stress and elucidate the mechanisms employed by the salt-tolerant microorganisms in improving plant tolerance under saline environments.
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Affiliation(s)
- Swarnendu Roy
- Plant Biochemistry Laboratory, Department of Botany, University of North Bengal, Darjeeling, West Bengal, India
| | | | - Rakhi Chakraborty
- Department of Botany, Acharya Prafulla Chandra Roy Government College, Darjeeling, West Bengal, India
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18
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Geng S, Ren Z, Liang L, Zhang Y, Li Z, Zhou Y, Duan L. An ABA Functional Analogue B2 Enhanced Salt Tolerance by Inducing the Root Elongation and Reducing Peroxidation Damage in Maize Seedlings. Int J Mol Sci 2021; 22:ijms222312986. [PMID: 34884788 PMCID: PMC8657829 DOI: 10.3390/ijms222312986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 12/27/2022] Open
Abstract
Salt stress negatively affects maize growth and yield. Application of plant growth regulator is an effective way to improve crop salt tolerance, therefore reducing yield loss by salt stress. Here, we used a novel plant growth regulator B2, which is a functional analogue of ABA. With the aim to determine whether B2 alleviates salt stress on maize, we studied its function under hydroponic conditions. When the second leaf was fully developed, it was pretreated with 100 µM ABA, 0.01 µM B2, 0.1 µM B2, and 1 µM B2, independently. After 5 days treatment, NaCl was added into the nutrient solution for salt stress. Our results showed that B2 could enhance salt tolerance in maize, especially when the concentration was 1.0 µMol·L−1. Exogenous application of B2 significantly enhanced root growth, and the root/shoot ratio increased by 7.6% after 6 days treatment under salt stress. Compared with control, the ABA level also decreased by 31% after 6 days, which might have resulted in the root development. What is more, B2 maintained higher photosynthetic capacity in maize leaves under salt stress conditions and increased the activity of antioxidant enzymes and decreased the generation rate of reactive oxygen species by 16.48%. On the other hand, B2 can enhance its water absorption ability by increasing the expression of aquaporin genes ZmPIP1-1 and ZmPIP1-5. In conclusion, the novel plant growth regulator B2 can effectively improve the salt tolerance in maize.
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Affiliation(s)
- Shiying Geng
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
| | - Zhaobin Ren
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
| | - Lijun Liang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
| | - Yumei Zhang
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China;
| | - Zhaohu Li
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
| | - Yuyi Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
- Correspondence: (Y.Z.); (L.D.); Tel.: +86-13811849849 (Y.Z.); +86-18601272095 (L.D.)
| | - Liusheng Duan
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China; (S.G.); (Z.R.); (L.L.); (Z.L.)
- Correspondence: (Y.Z.); (L.D.); Tel.: +86-13811849849 (Y.Z.); +86-18601272095 (L.D.)
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19
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Mishra P, Mishra J, Arora NK. Plant growth promoting bacteria for combating salinity stress in plants - Recent developments and prospects: A review. Microbiol Res 2021; 252:126861. [PMID: 34521049 DOI: 10.1016/j.micres.2021.126861] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 01/16/2023]
Abstract
Soil salinity has emerged as a great threat to the agricultural ecosystems throughout the globe. Many continents of the globe are affected by salinity and crop productivity is severely affected. Anthropogenic activities leading to the degradation of agricultural land have also accelerated the rate of salinization in arid and semi-arid regions. Several approaches are being evaluated for remediating saline soil and restoring their productivity. Amongst these, utilization of plant growth promoting bacteria (PGPB) has been marked as a promising tool. This greener approach is suitable for simultaneous reclamation of saline soil and improving the productivity. Salt-tolerant PGPB utilize numerous mechanisms that affect physiological, biochemical, and molecular responses in plants to cope with salt stress. These mechanisms include osmotic adjustment by ion homeostasis and osmolyte accumulation, protection from free radicals by the formation of free radicals scavenging enzymes, oxidative stress responses and maintenance of growth parameters by the synthesis of phytohormones and other metabolites. As salt-tolerant PGPB elicit better plant survival under salinity, they are the potential candidates for enhancing agricultural productivity. The present review focuses on the various mechanisms used by PGPB to improve plant health under salinity. Recent developments and prospects to facilitate better understanding on the functioning of PGPB for ameliorating salt stress in plants are emphasized.
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Affiliation(s)
- Priya Mishra
- Department of Environmental Science, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, 226025, India.
| | - Jitendra Mishra
- Department of Environmental Science, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, 226025, India.
| | - Naveen Kumar Arora
- Department of Environmental Science, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, 226025, India.
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20
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de Moraes ACP, Ribeiro LDS, de Camargo ER, Lacava PT. The potential of nanomaterials associated with plant growth-promoting bacteria in agriculture. 3 Biotech 2021; 11:318. [PMID: 34194902 PMCID: PMC8190246 DOI: 10.1007/s13205-021-02870-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 05/31/2021] [Indexed: 01/18/2023] Open
Abstract
The impacts of chemical fertilizers and pesticides have raised public concerns regarding the sustainability and security of food supplies, prompting the investigation of alternative methods that have combinations of both agricultural and environmental benefits, such as the use of biofertilizers involving microbes. These types of microbial inoculants are living microorganisms that colonize the soil or plant tissues when applied to the soil, seeds, or plant surfaces, facilitating plant nutrient acquisition. They can enhance plant growth by transforming nutrients into a form assimilable by plants and by acting as biological control agents, known as plant growth-promoting bacteria. The potential use of bacteria as biofertilizers in agriculture constitutes an economical and eco-friendly way to reduce the use of chemical fertilizers and pesticides. In this context, nanotechnology has emerged as a new source of quality enrichment for the agricultural sector. The use of nanoparticles can be an effective method to meet the challenges regarding the effectiveness of biofertilizers in natural environments. Given the novel sustainable strategies applied in agricultural systems, this review addresses the effects of nanoparticles on beneficial plant bacteria for promoting plant growth.
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Affiliation(s)
- Amanda Carolina Prado de Moraes
- Laboratory of Microbiology and Biomolecules, Department of Morphology and Pathology, Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
- Biotechnology Graduation Program (PPG-Biotec), Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
| | - Lucas da Silva Ribeiro
- Interdisciplinary Laboratory of Electrochemistry and Ceramics, Department of Chemistry, Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
| | - Emerson Rodrigues de Camargo
- Interdisciplinary Laboratory of Electrochemistry and Ceramics, Department of Chemistry, Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
| | - Paulo Teixeira Lacava
- Laboratory of Microbiology and Biomolecules, Department of Morphology and Pathology, Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
- Biotechnology Graduation Program (PPG-Biotec), Federal University of São Carlos (UFSCar), Rod. Washington Luiz, s/n, São Carlos, 13565-905 Brazil
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21
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Verma SK, Sahu PK, Kumar K, Pal G, Gond SK, Kharwar RN, White JF. Endophyte roles in nutrient acquisition, root system architecture development and oxidative stress tolerance. J Appl Microbiol 2021; 131:2161-2177. [PMID: 33893707 DOI: 10.1111/jam.15111] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 01/01/2023]
Abstract
Plants associate with communities of microbes (bacteria and fungi) that play critical roles in plant development, nutrient acquisition and oxidative stress tolerance. The major share of plant microbiota is endophytes which inhabit plant tissues and help them in various capacities. In this article, we have reviewed what is presently known with regard to how endophytic microbes interact with plants to modulate root development, branching, root hair formation and their implications in overall plant development. Endophytic microbes link the interactions of plants, rhizospheric microbes and soil to promote nutrient solubilization and further vectoring these nutrients to the plant roots making the soil-plant-microbe continuum. Further, plant roots internalize microbes and oxidatively extract nutrients from microbes in the rhizophagy cycle. The oxidative interactions between endophytes and plants result in the acquisition of nutrients by plants and are also instrumental in oxidative stress tolerance of plants. It is evident that plants actively cultivate microbes internally, on surfaces and in soils to acquire nutrients, modulate development and improve health. Understanding this continuum could be of greater significance in connecting endophytes with the hidden half of the plant that can also be harnessed in applied terms to enhance nutrient acquisition through the development of favourable root system architecture for sustainable production under stress conditions.
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Affiliation(s)
- S K Verma
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - P K Sahu
- National Bureau of Agriculturally Important Microorganism, Mau, Uttar Pradesh, India
| | - K Kumar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - G Pal
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - S K Gond
- Botany Section, MMV, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - R N Kharwar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - J F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
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Diagne N, Ndour M, Djighaly PI, Ngom D, Ngom MCN, Ndong G, Svistoonoff S, Cherif-Silini H. Effect of Plant Growth Promoting Rhizobacteria (PGPR) and Arbuscular Mycorrhizal Fungi (AMF) on Salt Stress Tolerance of Casuarina obesa (Miq.). FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.601004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Salinity is one of the main abiotic stresses limiting plant growth and development. However, the use of salt-tolerant plants combined with beneficial soil microorganisms could improve the effectiveness of biological methods for saline soil recovery. The aim of this study is to identify the Casuarina obesa/ Arbuscular Mycorrhizal fungi (AMF)/Plant Growth Promoting Rhizobacteria (PGPR) association that could be used in salt-land rehabilitation programs. Thus, the plants were grown under greenhouse on sandy soil, inoculated either with PGPR (Pantoea agglomerans and Bacillus sp.), or with AMF (Rhizophagus fasciculatus and Rhizophagus aggregatum) or co inoculated with PGPR and AMF and watered with a saline solution (0, 150, and 300 mM). After 4 months of cultivation, the plants were harvested and the results obtained showed that inoculation improves the survival rate, height and biomass of the plants compared to the control plants. The results also showed that inoculation increases the total amount of chlorophyll and the accumulation of plant proline at all levels of salt concentration. However, P. agglomerans and Bacillus sp. strains alone or in combination with R. fasciculatus increased plant growth. This study showed that these strains of PGPR, whether or not associated with AMF, could be biological tools to improve C. obesa performance under saline stress conditions.
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Rice SST Variation Shapes the Rhizosphere Bacterial Community, Conferring Tolerance to Salt Stress through Regulating Soil Metabolites. mSystems 2020; 5:5/6/e00721-20. [PMID: 33234605 PMCID: PMC7687028 DOI: 10.1128/msystems.00721-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Soil salinization is one of the major environmental stresses limiting crop productivity. Crops in agricultural ecosystems have developed various strategies to adapt to salt stress. We used rice mutant and CRISPR-edited lines to investigate the relationships among the Squamosa promoter Binding Protein box (SBP box) family gene (SST/OsSPL10), soil metabolites, and the rhizosphere bacterial community. We found that during salt stress, there are significant differences in the rhizosphere bacterial community and soil metabolites between the plants with the SST gene and those without it. Our findings provide a useful paradigm for revealing the roles of key genes of plants in shaping rhizosphere microbiomes and their relationships with soil metabolites and offer new insights into strategies to enhance rice tolerance to high salt levels from microbial and ecological perspectives. Some plant-specific resistance genes could affect rhizosphere microorganisms by regulating the release of root exudates. In a previous study, the SST (seedling salt tolerant) gene in rice (Oryza sativa) was identified, and loss of SST function resulted in better plant adaptation to salt stress. However, whether the rice SST variation could alleviate salt stress via regulating soil metabolites and microbiota in the rhizosphere is still unknown. Here, we used transgenic plants with SST edited in the Huanghuazhan (HHZ) and Zhonghua 11 (ZH11) cultivars by the CRISPR/Cas9 system and found that loss of SST function increased the accumulation of potassium and reduced the accumulation of sodium ions in rice plants. Using 16S rRNA gene amplicon high-throughput sequencing, we found that the mutant material shifted the rhizobacterial assembly under salt-free stress. Importantly, under salt stress, the sst, HHZcas, and ZH11cas plants significantly changed the assembly of the rhizobacteria. Furthermore, the rice SST gene also affected the soil metabolites, which were closely related to the dynamics of rhizosphere microbial communities, and we further determined the relationship between the rhizosphere microbiota and soil metabolites. Overall, our results show the effects of the rice SST gene on the response to salt stress associated with the soil microbiota and metabolites in the rhizosphere. This study reveals a helpful linkage among the rice SST gene, soil metabolites, and rhizobacterial community assembly and also provides a theoretical basis for improving crop adaptation through soil microbial management practices. IMPORTANCE Soil salinization is one of the major environmental stresses limiting crop productivity. Crops in agricultural ecosystems have developed various strategies to adapt to salt stress. We used rice mutant and CRISPR-edited lines to investigate the relationships among the Squamosa promoter Binding Protein box (SBP box) family gene (SST/OsSPL10), soil metabolites, and the rhizosphere bacterial community. We found that during salt stress, there are significant differences in the rhizosphere bacterial community and soil metabolites between the plants with the SST gene and those without it. Our findings provide a useful paradigm for revealing the roles of key genes of plants in shaping rhizosphere microbiomes and their relationships with soil metabolites and offer new insights into strategies to enhance rice tolerance to high salt levels from microbial and ecological perspectives.
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Pandey S, Gupta S. Diversity analysis of ACC deaminase producing bacteria associated with rhizosphere of coconut tree (Cocos nucifera L.) grown in Lakshadweep islands of India and their ability to promote plant growth under saline conditions. J Biotechnol 2020; 324:183-197. [PMID: 33164860 DOI: 10.1016/j.jbiotec.2020.10.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 09/16/2020] [Accepted: 10/19/2020] [Indexed: 02/06/2023]
Abstract
ACC deaminase producing Plant growth promoting rhizobacteria (PGPR) offers a great promise for ameliorating the negative impacts of salinity stress manifested on plants. In this context, 28 rhizospheric bacteria associated with ACC deaminase potential (198-1069 nmol α-ketobutyrate mg protein-1 h-1) were isolated from 5 different islands of Lakshadweep, union territory, India- Agatti, Kavaratti, Bangaram, Kadmat, and Thinnakara islands using DF-minimal medium. The diversity of cultivable ACC deaminase producing bacteria was analysed by PCR-RFLP (Restriction Fragment Length Polymorphism) method using three endonucleases AluI, MspI and HaeIII which led to the grouping of these isolates into six clusters at 80 % similarity index. Subsequently, isolates were functionally characterized for various PGP traits such that indole-3-acetic acid (IAA) production (∼10-80 μg mL-1); 16 isolates had phosphate solubilizing potential ranging from ∼19 to 88 P mg L-1 ; siderophore and ammonia production abilities were observed in 5 and 24 isolates, respectively while two strains tolerated up to 8% NaCl. Phylogenetic analysis of 16S rRNA gene sequences of representative strain from each cluster revealed that twenty-eight ACC deaminase producing PGPR belong to eight distinct genera: Pseudomonas, Bacillus, Azospirillum, Azotobacter, Escherichia, Paenibacillus, Burkholderia, and Klebsiella. Two isolates, CO1 (Pseudomonas putida) and CO8 (Bacillus paramycoides) were evaluated for plant growth promoting effects on French bean (Phaseolus vulgaris) under salinity (100 mM NaCl) stress. Both the selected isolates in consortium form significantly increased the root length, shoot length, root fresh and dry weight, shoot fresh and dry weight of French bean seedlings exposed to salinity stress, compared to non-inoculated control plants. The co-inoculation with selected strains CO1 and CO8 has significantly improved chlorophyll concentration, relative water content, membrane stability index, gas exchange parameters including net photosynthesis rate (PN), stomatal conductance (gs), transpiration rate (E) and water use efficiency of French bean plants by ∼100 %, ∼85 %, ∼40 %, ∼198 %, ∼80 %, ∼70 % and ∼75 %, respectively under saline conditions in comparison with non-inoculated plants. Moreover, the consortium treated French bean plants showed lower levels of stress-induced ethylene by 38 %, electrolyte leakage and Malondialdehyde (MDA) content by ∼15 % under salt stress compared to non-inoculated ones. This study unveiled the potential of halotolerant strains, Pseudomonas putida and Bacillus paramycoides as French bean biofertilizers in mitigating the adverse effects of salinity in plant growth in sustainable agriculture.
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Affiliation(s)
- Sangeeta Pandey
- Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh 201313, India.
| | - Shikha Gupta
- I-2 block, AIOA, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh 201313, India
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Bhat MA, Kumar V, Bhat MA, Wani IA, Dar FL, Farooq I, Bhatti F, Koser R, Rahman S, Jan AT. Mechanistic Insights of the Interaction of Plant Growth-Promoting Rhizobacteria (PGPR) With Plant Roots Toward Enhancing Plant Productivity by Alleviating Salinity Stress. Front Microbiol 2020; 11:1952. [PMID: 32973708 PMCID: PMC7468593 DOI: 10.3389/fmicb.2020.01952] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/24/2020] [Indexed: 11/20/2022] Open
Abstract
Agriculture plays an important role in a country's economy. The sector is challenged by many stresses, which led to huge loss in plant productivity worldwide. The ever-increasing population, rapid urbanization with shrinking agricultural lands, dramatic change in climatic conditions, and extensive use of agrochemicals in agricultural practices that caused environmental disturbances confront mankind of escalating problems of food security and sustainability in agriculture. Escalating environmental problems and global hunger have led to the development and adoption of genetic engineering and other conventional plant breeding approaches in developing stress-tolerant varieties of crops. However, these approaches have drawn flaws in their adoption as the process of generating tolerant varieties takes months to years in bringing the technology from the lab to the field. Under such scenario, sustainable and climate-smart agricultural practices that avail bacterial usage open the avenues in fulfilling the incessant demand for food for the global population. Ensuring stability on economic fronts, bacteria minimizes plant salt uptake by trapping ions in their exopolysaccharide matrix besides checking the expression of Na+/H+ and high-affinity potassium transporters. Herein we describe information on salinity stress and its effect on plant health as well as strategies adopted by plant growth-promoting rhizobacteria (PGPR) in helping plants to overcome salinity stress and in mitigating loss in overall plant productivity. It is believed that acquisition of advanced knowledge of plant-beneficial PGPR will help in devising strategies for sustainable, environment-friendly, and climate-smart agricultural technologies for adoption in agriculture to overcome the constrained environmental conditions.
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Affiliation(s)
- Mujtaba Aamir Bhat
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Vijay Kumar
- Department of Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Mudasir Ahmad Bhat
- Department of Biotechnology, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Ishfaq Ahmad Wani
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Farhana Latief Dar
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Iqra Farooq
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Farha Bhatti
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Rubina Koser
- Department of Microbiology, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
| | - Safikur Rahman
- Department of Botany, Munshi Singh College, Babasaheb Bhimrao Ambedkar Bihar University, Muzaffarpur, India
| | - Arif Tasleem Jan
- Department of Botany, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
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Saline and Arid Soils: Impact on Bacteria, Plants, and their Interaction. BIOLOGY 2020; 9:biology9060116. [PMID: 32498442 PMCID: PMC7344409 DOI: 10.3390/biology9060116] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022]
Abstract
Salinity and drought are the most important abiotic stresses hampering crop growth and yield. It has been estimated that arid areas cover between 41% and 45% of the total Earth area worldwide. At the same time, the world’s population is going to soon reach 9 billion and the survival of this huge amount of people is dependent on agricultural products. Plants growing in saline/arid soil shows low germination rate, short roots, reduced shoot biomass, and serious impairment of photosynthetic efficiency, thus leading to a substantial loss of crop productivity, resulting in significant economic damage. However, plants should not be considered as single entities, but as a superorganism, or a holobiont, resulting from the intimate interactions occurring between the plant and the associated microbiota. Consequently, it is very complex to define how the plant responds to stress on the basis of the interaction with its associated plant growth-promoting bacteria (PGPB). This review provides an overview of the physiological mechanisms involved in plant survival in arid and saline soils and aims at describing the interactions occurring between plants and its bacteriome in such perturbed environments. The potential of PGPB in supporting plant survival and fitness in these environmental conditions has been discussed.
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Bukhat S, Imran A, Javaid S, Shahid M, Majeed A, Naqqash T. Communication of plants with microbial world: Exploring the regulatory networks for PGPR mediated defense signaling. Microbiol Res 2020; 238:126486. [PMID: 32464574 DOI: 10.1016/j.micres.2020.126486] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/20/2020] [Accepted: 03/28/2020] [Indexed: 02/01/2023]
Abstract
Agricultural manipulation of potentially beneficial rhizosphere microbes is increasing rapidly due to their multi-functional plant-protective and growth related benefits. Plant growth promoting rhizobacteria (PGPR) are mostly non-pathogenic microbes which exert direct benefits on plants while there are rhizosphere bacteria which indirectly help plant by ameliorating the biotic and/or abiotic stress or induction of defense response in plant. Regulation of these direct or indirect effect takes place via highly specialized communication system induced at multiple levels of interaction i.e., inter-species, intra-species, and inter-kingdom. Studies have provided insights into the functioning of signaling molecules involved in communication and induction of defense responses. Activation of host immune responses upon bacterial infection or rhizobacteria perception requires comprehensive and precise gene expression reprogramming and communication between hosts and microbes. Majority of studies have focused on signaling of host pattern recognition receptors (PRR) and nod-like receptor (NLR) and microbial effector proteins under mining the role of other components such as mitogen activated protein kinase (MAPK), microRNA, histone deacytylases. The later ones are important regulators of gene expression reprogramming in plant immune responses, pathogen virulence and communications in plant-microbe interactions. During the past decade, inoculation of PGPR has emerged as potential strategy to induce biotic and abiotic stress tolerance in plants; hence, it is imperative to expose the basis of these interactions. This review discusses microbes and plants derived signaling molecules for their communication, regulatory and signaling networks of PGPR and their different products that are involved in inducing resistance and tolerance in plants against environmental stresses and the effect of defense signaling on root microbiome. We expect that it will lead to the development and exploitation of beneficial microbes as source of crop biofertilizers in climate changing scenario enabling more sustainable agriculture.
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Affiliation(s)
- Sherien Bukhat
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, 60800 Multan, Pakistan.
| | - Asma Imran
- National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O. Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Shaista Javaid
- Institute of Molecular Biology and Biotechnology, University of Lahore Main Campus, Defense road, Lahore, Pakistan.
| | - Muhammad Shahid
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad 38000, Pakistan.
| | - Afshan Majeed
- Department of Soil and Environmental Sciences, The University of Poonch, Rawalakot, Azad Jammu and Kashmir, Pakistan.
| | - Tahir Naqqash
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, 60800 Multan, Pakistan.
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28
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Li Z, Cheng B, Zeng W, Zhang X, Peng Y. Proteomic and Metabolomic Profilings Reveal Crucial Functions of γ-Aminobutyric Acid in Regulating Ionic, Water, and Metabolic Homeostasis in Creeping Bentgrass under Salt Stress. J Proteome Res 2020; 19:769-780. [PMID: 31916766 DOI: 10.1021/acs.jproteome.9b00627] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The global emergence of soil salinization poses a serious challenge to many countries and regions. γ-Aminobutyric acid (GABA) is involved in systemic regulation of plant adaptation to salt stress but the underlying molecular and metabolic mechanism still remains largely unknown. The elevated endogenous GABA level by the application of exogenous GABA improved salt tolerance associated with the enhancement of antioxidant capacity, photosynthetic characteristics, osmotic adjustment (OA), and water use efficiency in creeping bentgrass. GABA strongly upregulated transcript levels of AsPPa2, AsATPaB2, AsNHX2/4/6, and AsSOS1/20 in roots involved in enhanced capacity of Na+ compartmentalization and mitigation of Na+ toxicity in the cytosol. Significant downregulation of AsHKT1/4 expression could be induced by GABA in leaves in relation to maintenance of the significantly lower Na+ content and higher K+/Na+ ratio. GABA-depressed aquaporin expression and accumulation induced declines in stomatal conductance and transpiration, thereby reducing water loss in leaves during salt stress. For metabolic regulation, GABA primarily enhanced sugar and amino acid accumulation and metabolism, largely contributing to improved salt tolerance through maintaining OA and metabolic homeostasis. Other major pathways could be related to GABA-induced salt tolerance including increases in antioxidant defense, heat shock proteins, and myo-inositol accumulation in leaves. Integrative analyses of molecular, protein, metabolic, and physiological changes reveal systemic functions of GABA in regulating ionic, water, and metabolic homeostasis in nonhalophytic creeping bentgrass under salt stress.
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Affiliation(s)
- Zhou Li
- Department of Grassland Science, College of Animal Science and Technology , Sichuan Agricultural University , Chengdu 611130 , China
| | - Bizhen Cheng
- Department of Grassland Science, College of Animal Science and Technology , Sichuan Agricultural University , Chengdu 611130 , China
| | - Weihang Zeng
- Department of Grassland Science, College of Animal Science and Technology , Sichuan Agricultural University , Chengdu 611130 , China
| | - Xinquan Zhang
- Department of Grassland Science, College of Animal Science and Technology , Sichuan Agricultural University , Chengdu 611130 , China
| | - Yan Peng
- Department of Grassland Science, College of Animal Science and Technology , Sichuan Agricultural University , Chengdu 611130 , China
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29
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Chen Q, Meyer WA, Zhang Q, White JF. 16S rRNA metagenomic analysis of the bacterial community associated with turf grass seeds from low moisture and high moisture climates. PeerJ 2020; 8:e8417. [PMID: 31942261 PMCID: PMC6956778 DOI: 10.7717/peerj.8417] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/16/2019] [Indexed: 12/19/2022] Open
Abstract
Turfgrass investigators have observed that plantings of grass seeds produced in moist climates produce seedling stands that show greater stand evenness with reduced disease compared to those grown from seeds produced in dry climates. Grass seeds carry microbes on their surfaces that become endophytic in seedlings and promote seedling growth. We hypothesize that incomplete development of the microbiome associated with the surface of seeds produced in dry climates reduces the performance of seeds. Little is known about the influence of moisture on the structure of this microbial community. We conducted metagenomic analysis of the bacterial communities associated with seeds of three turf species (Festuca rubra, Lolium arundinacea, and Lolium perenne) from low moisture (LM) and high moisture (HM) climates. The bacterial communities were characterized by Illumina high-throughput sequencing of 16S rRNA V3–V4 regions. We performed seed germination tests and analyzed the correlations between the abundance of different bacterial groups and seed germination at different taxonomy ranks. Climate appeared to structure the bacterial communities associated with seeds. LM seeds vectored mainly Proteobacteria (89%). HM seeds vectored a denser and more diverse bacterial community that included Proteobacteria (50%) and Bacteroides (39%). At the genus level, Pedobacter (20%), Sphingomonas (13%), Massilia (12%), Pantoea (12%) and Pseudomonas (11%) were the major genera in the bacterial communities regardless of climate conditions. Massilia, Pantoea and Pseudomonas dominated LM seeds, while Pedobacter and Sphingomonas dominated HM seeds. The species of turf seeds did not appear to influence bacterial community composition. The seeds of the three turf species showed a core microbiome consisting of 27 genera from phyla Actinobacteria, Bacteroidetes, Patescibacteria and Proteobacteria. Differences in seed-vectored microbes, in terms of diversity and density between high and LM climates, may result from effects of moisture level on the colonization of microbes and the development of microbe community on seed surface tissues (adherent paleas and lemmas). The greater diversity and density of seed vectored microbes in HM climates may benefit seedlings by helping them tolerate stress and fight disease organisms, but this dense microbial community may also compete with seedlings for nutrients, slowing or modulating seed germination and seedling growth.
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Affiliation(s)
- Qiang Chen
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - William A Meyer
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Qiuwei Zhang
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - James F White
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
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30
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Zhang J, Wang P, Tian H, Tao Z, Guo T. Transcriptome Analysis of Ice Plant Growth-Promoting Endophytic Bacterium Halomonas sp. Strain MC1 to Identify the Genes Involved in Salt Tolerance. Microorganisms 2020; 8:E88. [PMID: 31936448 PMCID: PMC7022971 DOI: 10.3390/microorganisms8010088] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/27/2019] [Accepted: 01/04/2020] [Indexed: 12/27/2022] Open
Abstract
Salt stress is an important adverse condition encountered during plant and microbe growth in terrestrial soil ecosystems. Currently, how ice plant (Mesembryanthemum crystallinum) growth-promoting endophytic bacteria (EB) cope with salt stress and regulate growth and the genes responsible for salt tolerance remain unknown. We applied RNA-Seq technology to determine the growth mechanism of the EB Halomonas sp. MC1 strain and the genes involved in salt tolerance. A total of 893 genes were significantly regulated after salt treatment. These genes included 401 upregulated and 492 downregulated genes. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes analysis revealed that the most enriched genes included those related to the outer membrane-bounded periplasmic space, ATPase activity, catabolic process, and proton transmembrane transport. The quantitative real-time polymerase chain reaction data were similar to those obtained from RNA-Seq. The MC1 strain maintained survival under salt stress by regulating cellular and metabolic processes and pyruvate metabolism pathways such as organic and carboxylic acid catabolic pathways. We highlighted the response mechanism of Halomonas sp. MC1 to fully understand the dynamics of complex salt-microbe interactions.
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Affiliation(s)
- Jian Zhang
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China (Z.T.)
- Key Laboratory of Genetic Improvement and Ecophysiology of Horticultural Crops, Hefei 230031, Anhui, China
| | - Pengcheng Wang
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China (Z.T.)
- Key Laboratory of Genetic Improvement and Ecophysiology of Horticultural Crops, Hefei 230031, Anhui, China
| | - Hongmei Tian
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China (Z.T.)
- Key Laboratory of Genetic Improvement and Ecophysiology of Horticultural Crops, Hefei 230031, Anhui, China
| | - Zhen Tao
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China (Z.T.)
| | - Tingting Guo
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China (Z.T.)
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
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31
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Saia S, Aissa E, Luziatelli F, Ruzzi M, Colla G, Ficca AG, Cardarelli M, Rouphael Y. Growth-promoting bacteria and arbuscular mycorrhizal fungi differentially benefit tomato and corn depending upon the supplied form of phosphorus. MYCORRHIZA 2020; 30:133-147. [PMID: 31823026 DOI: 10.1007/s00572-019-00927-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/20/2019] [Indexed: 05/08/2023]
Abstract
The ability of plants to take up phosphorus (P) from soil depends on root morphology and root exudates release and can be modulated by beneficial soil microbes. These microbes can solubilize P, affect root elongation and branching, and lead to a higher uptake of P and other nutrients. However, coordination of these mechanisms is unclear, especially the mechanism for changing the available form of P. We aimed to dissect the effects of two different beneficial microbial taxa (plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF)) on root morphological traits, plant nutrient content, and growth in tomato and corn fertilized with either Gafsa rock phosphate (RP) or triple superphosphate (TSP), which have contrasting solubility levels. Tomato and corn were grown in pots and inoculated with one of three PGPB species or a mix of two AMF species or were not inoculated. Root traits, botanical fractions, and the contents of various mineral nutrients were measured. TSP stimulated tomato biomass accumulation compared to RP but did not stimulate corn biomass accumulation. PGPB improved the growth of both plant species under RP, with limited differences among the strains, whereas AMF only improved tomato growth under TSP. These differences between microbial systems were explained by a bacterial effect on the total root length but not on the mean root diameter and by the ability of AMF to improve the mineral nutrient content. The effects of PGPB were less dependent on the plant species and on P form than the effects of AMF.These results have implications for the improvement of the early plant growth through the management of beneficial microbes.
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Affiliation(s)
- Sergio Saia
- Council for Agricultural Research and Economics (CREA), Research Centre for Cereal and Industrial Crops (CREA-CI), Vercelli, Italy
| | - Echrak Aissa
- Department of Agriculture and Forest Sciences, University of Tuscia, Viterbo, Italy
- National Agronomic Institute of Tunisia, Tunis, Tunisia
| | - Francesca Luziatelli
- Department for Innovation in Biological, Agrofood and Forest Systems, University of Tuscia, Viterbo, Italy
| | - Maurizio Ruzzi
- Department for Innovation in Biological, Agrofood and Forest Systems, University of Tuscia, Viterbo, Italy
| | - Giuseppe Colla
- Department of Agriculture and Forest Sciences, University of Tuscia, Viterbo, Italy
| | - Anna Grazia Ficca
- Department for Innovation in Biological, Agrofood and Forest Systems, University of Tuscia, Viterbo, Italy
| | - Mariateresa Cardarelli
- Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria (CREA), Centro di Ricerca Orticoltura e Florovivaismo (CREA-OF), Pontecagnano Faiano, Italy.
| | - Youssef Rouphael
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy.
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32
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Egamberdieva D, Wirth S, Bellingrath-Kimura SD, Mishra J, Arora NK. Salt-Tolerant Plant Growth Promoting Rhizobacteria for Enhancing Crop Productivity of Saline Soils. Front Microbiol 2019; 10:2791. [PMID: 31921005 PMCID: PMC6930159 DOI: 10.3389/fmicb.2019.02791] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/18/2019] [Indexed: 11/13/2022] Open
Abstract
Soil salinity has emerged as a serious issue for global food security. It is estimated that currently about 62 million hectares or 20 percent of the world's irrigated land is affected by salinity. The deposition of an excess amount of soluble salt in cultivable land directly affects crop yields. The uptake of high amount of salt inhibits diverse physiological and metabolic processes of plants even impacting their survival. The conventional methods of reclamation of saline soil which involve scraping, flushing, leaching or adding an amendment (e.g., gypsum, CaCl2, etc.) are of limited success and also adversely affect the agro-ecosystems. In this context, developing sustainable methods which increase the productivity of saline soil without harming the environment are necessary. Since long, breeding of salt-tolerant plants and development of salt-resistant crop varieties have also been tried, but these and aforesaid conventional approaches are not able to solve the problem. Salt tolerance and dependence are the characteristics of some microbes. Salt-tolerant microbes can survive in osmotic and ionic stress. Various genera of salt-tolerant plant growth promoting rhizobacteria (ST-PGPR) have been isolated from extreme alkaline, saline, and sodic soils. Many of them are also known to mitigate various biotic and abiotic stresses in plants. In the last few years, potential PGPR enhancing the productivity of plants facing salt-stress have been researched upon suggesting that ST-PGPR can be exploited for the reclamation of saline agro-ecosystems. In this review, ST-PGPR and their potential in enhancing the productivity of saline agro-ecosystems will be discussed. Apart from this, PGPR mediated mechanisms of salt tolerance in different crop plants and future research trends of using ST-PGPR for reclamation of saline soils will also be highlighted.
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Affiliation(s)
- Dilfuza Egamberdieva
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
- Faculty of Biology, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Stephan Wirth
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | | | - Jitendra Mishra
- DST-CPR, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Naveen K. Arora
- Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Lucknow, India
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33
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Bezerra-Neto JP, de Araújo FC, Ferreira-Neto JRC, da Silva MD, Pandolfi V, Aburjaile FF, Sakamoto T, de Oliveira Silva RL, Kido EA, Barbosa Amorim LL, Ortega JM, Benko-Iseppon AM. Plant Aquaporins: Diversity, Evolution and Biotechnological Applications. Curr Protein Pept Sci 2019; 20:368-395. [PMID: 30387391 DOI: 10.2174/1389203720666181102095910] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/24/2018] [Accepted: 10/30/2018] [Indexed: 12/20/2022]
Abstract
The plasma membrane forms a permeable barrier that separates the cytoplasm from the external environment, defining the physical and chemical limits in each cell in all organisms. The movement of molecules and ions into and out of cells is controlled by the plasma membrane as a critical process for cell stability and survival, maintaining essential differences between the composition of the extracellular fluid and the cytosol. In this process aquaporins (AQPs) figure as important actors, comprising highly conserved membrane proteins that carry water, glycerol and other hydrophilic molecules through biomembranes, including the cell wall and membranes of cytoplasmic organelles. While mammals have 15 types of AQPs described so far (displaying 18 paralogs), a single plant species can present more than 120 isoforms, providing transport of different types of solutes. Such aquaporins may be present in the whole plant or can be associated with different tissues or situations, including biotic and especially abiotic stresses, such as drought, salinity or tolerance to soils rich in heavy metals, for instance. The present review addresses several aspects of plant aquaporins, from their structure, classification, and function, to in silico methodologies for their analysis and identification in transcriptomes and genomes. Aspects of evolution and diversification of AQPs (with a focus on plants) are approached for the first time with the aid of the LCA (Last Common Ancestor) analysis. Finally, the main practical applications involving the use of AQPs are discussed, including patents and future perspectives involving this important protein family.
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Affiliation(s)
- João P Bezerra-Neto
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Flávia Czekalski de Araújo
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - José R C Ferreira-Neto
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Manassés D da Silva
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Valesca Pandolfi
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Flavia F Aburjaile
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Tetsu Sakamoto
- Universidade Federal de Minas Gerais, Department of Biochemistry and Immunology, Belo Horizonte, Brazil
| | - Roberta L de Oliveira Silva
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Ederson A Kido
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
| | - Lidiane L Barbosa Amorim
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil.,Instituto Federal de Educação, Ciência e Tecnologia do Piauí, Campus Oeiras, Avenida Projetada, s/n, 64.500-000, Oeiras, Piauí, Brazil
| | - José M Ortega
- Universidade Federal de Minas Gerais, Department of Biochemistry and Immunology, Belo Horizonte, Brazil
| | - Ana M Benko-Iseppon
- Universidade Federal de Pernambuco, Genetics Department, Center of Biosciences, Av. Prof. Moraes Rego, 1235, 50.670-423, Recife, Pernambuco, Brazil
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Tackling Salinity in Sustainable Agriculture—What Developing Countries May Learn from Approaches of the Developed World. SUSTAINABILITY 2019. [DOI: 10.3390/su11174558] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Soil salinity is a common problem of the developing world as well as the developed world. However, the pace to reduce salinity is much slower in the developing world. The application of short-term approaches with an unsustainable supply of funds are the major reasons of low success. In contrast, the developed world has focused on long-term and sustainable techniques, and considerable funds per unit area have been allocated to reduce soil salinity. Here, we review the existing approaches in both worlds. Approaches like engineering and nutrient use were proven to be unsustainable, while limited breeding and biosaline approaches had little success in the developing countries. In contrast, advanced breeding and genetics tools were implemented in the developed countries to improve the salinity tolerance of different crops with more success. Resultantly, developed countries not only reduced the area for soil salinity at a higher rate, but more sustainable and cheaper ways to resolve the issue were implemented at the farmers’ field. Similarly, plant microbial approaches and the application of fertigation through drip irrigation have great potential for both worlds, and farmer participatory approaches are required to obtain fruitful outcomes. In this regard, a challenging issue is the transition of sustainable approaches from developed countries to developing ones, and possible methods for this are discussed.
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36
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Eida AA, Alzubaidy HS, de Zélicourt A, Synek L, Alsharif W, Lafi FF, Hirt H, Saad MM. Phylogenetically diverse endophytic bacteria from desert plants induce transcriptional changes of tissue-specific ion transporters and salinity stress in Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 280:228-240. [PMID: 30824001 DOI: 10.1016/j.plantsci.2018.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 05/02/2023]
Abstract
Salinity severely hampers crop productivity worldwide and plant growth promoting bacteria could serve as a sustainable solution to improve plant growth under salt stress. However, the molecular mechanisms underlying salt stress tolerance promotion by beneficial bacteria remain unclear. In this work, six bacterial isolates from four different desert plant species were screened for their biochemical plant growth promoting traits and salinity stress tolerance promotion of the unknown host plant Arabidopsis thaliana. Five of the isolates induced variable root phenotypes but could all increase plant shoot and root weight under salinity stress. Inoculation of Arabidopsis with five isolates under salinity stress resulted in tissue-specific transcriptional changes of ion transporters and reduced Na+/K+ shoot ratios. The work provides first insights into the possible mechanisms and the commonality by which phylogenetically diverse bacteria from different desert plants induce salinity stress tolerance in Arabidopsis. The bacterial isolates provide new tools for studying abiotic stress tolerance mechanisms in plants and a promising agricultural solution for increasing crop yields in semi-arid regions.
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Affiliation(s)
- Abdul Aziz Eida
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Hanin S Alzubaidy
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Axel de Zélicourt
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Lukáš Synek
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Wiam Alsharif
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Feras F Lafi
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
| | - Heribert Hirt
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia.
| | - Maged M Saad
- King Abdullah University of Science and Technology (KAUST), Desert Agriculture Initiative, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 6900-23955, Kingdom of Saudi Arabia, Saudi Arabia
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37
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Wang R, Wang M, Chen K, Wang S, Mur LAJ, Guo S. Exploring the Roles of Aquaporins in Plant⁻Microbe Interactions. Cells 2018; 7:E267. [PMID: 30545006 PMCID: PMC6316839 DOI: 10.3390/cells7120267] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/23/2018] [Accepted: 12/06/2018] [Indexed: 11/16/2022] Open
Abstract
Aquaporins (AQPs) are membrane channel proteins regulating the flux of water and other various small solutes across membranes. Significant progress has been made in understanding the roles of AQPs in plants' physiological processes, and now their activities in various plant⁻microbe interactions are receiving more attention. This review summarizes the various roles of different AQPs during interactions with microbes which have positive and negative consequences on the host plants. In positive plant⁻microbe interactions involving rhizobia, arbuscular mycorrhizae (AM), and plant growth-promoting rhizobacteria (PGPR), AQPs play important roles in nitrogen fixation, nutrient transport, improving water status, and increasing abiotic stress tolerance. For negative interactions resulting in pathogenesis, AQPs help plants resist infections by preventing pathogen ingress by influencing stomata opening and influencing defensive signaling pathways, especially through regulating systemic acquired resistance. Interactions with bacterial or viral pathogens can be directly perturbed through direct interaction of AQPs with harpins or replicase. However, whilst these observations indicate the importance of AQPs, further work is needed to develop a fuller mechanistic understanding of their functions.
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Affiliation(s)
- Ruirui Wang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
| | - Min Wang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
| | - Kehao Chen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
| | - Shiyu Wang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
| | - Luis Alejandro Jose Mur
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA, UK.
| | - Shiwei Guo
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
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38
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Verma SK, White JF. Indigenous endophytic seed bacteria promote seedling development and defend against fungal disease in browntop millet (Urochloa ramosa L.). J Appl Microbiol 2018; 124:764-778. [PMID: 29253319 DOI: 10.1111/jam.13673] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/22/2017] [Accepted: 12/11/2017] [Indexed: 11/29/2022]
Abstract
AIMS This study was conducted to investigate indigenous seed endophyte effects on browntop millet seedling development. We report that seed-inhabiting bacterial endophytes are responsible for promoting seedling development, including stimulation of root hair formation, increasing root and shoot length growth and increasing photosynthetic pigment content of seedlings. Bacterial endophytes also improved resistance of seedlings to disease. METHODS AND RESULTS A total of four endophytic bacteria were isolated from surface-sterilized seeds and identified by 16S rDNA sequencing as Curtobacterium sp. (M1), Microbacterium sp. (M2), Methylobacterium sp. (M3) and Bacillus amyloliquefaciens (M4). Removal of bacteria with streptomycin treatment from the seeds compromised seedling growth and development. When endophytes were reinoculated onto seeds, seedlings recovered normal development. Strains M3 and M4 were found to be most potent in promoting growth of seedlings. Bacteria were found to produce auxin, solubilize phosphate and inhibit fungal pathogens. Significant protection of seedlings from Fusarium infection was found using strain M4 in microcosm assays. The antifungal lipopeptide genes for surfactin and iturin were detected in M4; culture extracts of M4 showed a positive drop collapse result for surfactins. CONCLUSIONS This study demonstrates that browntop millet seeds vector indigenous endophytes that are responsible for modulation of seedling development and protection of seedlings from fungal disease. SIGNIFICANCE AND IMPACT OF THE STUDY This study is significant and original in that it is the first report of seed-inhabiting endophytes of browntop millet that influence seedling development and function in defence against soilborne pathogens. This study suggests that conservation and management of seed-vectored endophytes may be important in development of more sustainable agricultural practices.
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Affiliation(s)
- S K Verma
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA.,Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - J F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
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39
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Irizarry I, White J. Bacillus amyloliquefaciens
alters gene expression,
ROS
production and lignin synthesis in cotton seedling roots. J Appl Microbiol 2018; 124:1589-1603. [DOI: 10.1111/jam.13744] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/23/2018] [Accepted: 02/15/2018] [Indexed: 01/09/2023]
Affiliation(s)
- I. Irizarry
- Department of Plant Biology Rutgers University New Brunswick NJ USA
- Escuela de Ciencias Naturales y Tecnología Universidad del Turabo Gurabo Puerto Rico
| | - J.F. White
- Department of Plant Biology Rutgers University New Brunswick NJ USA
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40
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Lata R, Chowdhury S, Gond SK, White JF. Induction of abiotic stress tolerance in plants by endophytic microbes. Lett Appl Microbiol 2018; 66:268-276. [PMID: 29359344 DOI: 10.1111/lam.12855] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/13/2018] [Accepted: 01/14/2018] [Indexed: 12/01/2022]
Abstract
Endophytes are micro-organisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. SIGNIFICANCE AND IMPACT OF THE STUDY Increasing human populations demand more crop yield for food security while crop production is adversely affected by abiotic stresses like drought, salinity and high temperature. Development of stress tolerance in plants is a strategy to cope with the negative effects of adverse environmental conditions. Endophytes are well recognized for plant growth promotion and production of natural compounds. The property of endophytes to induce stress tolerance in plants can be applied to increase crop yields. With this review, we intend to promote application of endophytes in biotechnology and genetic engineering for the development of stress-tolerant plants.
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Affiliation(s)
- R Lata
- Department of Botany, MMV, Banaras Hindu University, Varanasi, India
| | - S Chowdhury
- Department of Botany, MMV, Banaras Hindu University, Varanasi, India
| | - S K Gond
- Department of Botany, MMV, Banaras Hindu University, Varanasi, India
| | - J F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
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41
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Etesami H, Beattie GA. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops. Front Microbiol 2018; 9:148. [PMID: 29472908 PMCID: PMC5809494 DOI: 10.3389/fmicb.2018.00148] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/23/2018] [Indexed: 11/20/2022] Open
Abstract
Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria) to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.
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Affiliation(s)
- Hassan Etesami
- Department of Soil Science, Faculty of Agricultural Engineering & Technology, University of Tehran, Tehran, Iran
| | - Gwyn A. Beattie
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
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42
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Rho H, Hsieh M, Kandel SL, Cantillo J, Doty SL, Kim SH. Do Endophytes Promote Growth of Host Plants Under Stress? A Meta-Analysis on Plant Stress Mitigation by Endophytes. MICROBIAL ECOLOGY 2018; 75:407-418. [PMID: 28840330 DOI: 10.1007/s00248-017-1054-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/07/2017] [Indexed: 05/18/2023]
Abstract
Endophytes are microbial symbionts living inside plants and have been extensively researched in recent decades for their functions associated with plant responses to environmental stress. We conducted a meta-analysis of endophyte effects on host plants' growth and fitness in response to three abiotic stress factors: drought, nitrogen deficiency, and excessive salinity. Ninety-four endophyte strains and 42 host plant species from the literature were evaluated in the analysis. Endophytes increased biomass accumulation of host plants under all three stress conditions. The stress mitigation effects by endophytes were similar among different plant taxa or functional groups with few exceptions; eudicots and C4 species gained more biomass than monocots and C3 species with endophytes, respectively, under drought conditions. Our analysis supports the effectiveness of endophytes in mitigating drought, nitrogen deficiency, and salinity stress in a wide range of host species with little evidence of plant-endophyte specificity.
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Affiliation(s)
- Hyungmin Rho
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA.
| | - Marian Hsieh
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Shyam L Kandel
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Johanna Cantillo
- Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
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43
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Verma SK, Kingsley K, Irizarry I, Bergen M, Kharwar RN, White JF. Seed-vectored endophytic bacteria modulate development of rice seedlings. J Appl Microbiol 2017; 122:1680-1691. [PMID: 28375579 DOI: 10.1111/jam.13463] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/26/2017] [Accepted: 03/28/2017] [Indexed: 11/30/2022]
Abstract
AIM The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. METHODS AND RESULTS Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. CONCLUSION Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development.
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Affiliation(s)
- S K Verma
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA.,Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, UP, India
| | - K Kingsley
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
| | - I Irizarry
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
| | - M Bergen
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
| | - R N Kharwar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, UP, India
| | - J F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
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Ledger T, Rojas S, Timmermann T, Pinedo I, Poupin MJ, Garrido T, Richter P, Tamayo J, Donoso R. Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana. Front Microbiol 2016; 7:1838. [PMID: 27909432 PMCID: PMC5112238 DOI: 10.3389/fmicb.2016.01838] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 11/01/2016] [Indexed: 01/09/2023] Open
Abstract
Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic stress tolerance by a Paraburkholderia species.
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Affiliation(s)
- Thomas Ledger
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center of Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
| | - Sandy Rojas
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
| | - Tania Timmermann
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center of Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
| | - Ignacio Pinedo
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
| | - María J. Poupin
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center of Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
| | - Tatiana Garrido
- Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Pablo Richter
- Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Javier Tamayo
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
| | - Raúl Donoso
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center of Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
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Microbially Mediated Plant Salt Tolerance and Microbiome-based Solutions for Saline Agriculture. Biotechnol Adv 2016; 34:1245-1259. [PMID: 27587331 DOI: 10.1016/j.biotechadv.2016.08.005] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 08/26/2016] [Accepted: 08/26/2016] [Indexed: 01/15/2023]
Abstract
Soil salinization adversely affects plant growth and has become one of the major limiting factors for crop productivity worldwide. The conventional approach, breeding salt-tolerant plant cultivars, has often failed to efficiently alleviate the situation. In contrast, the use of a diverse array of microorganisms harbored by plants has attracted increasing attention because of the remarkable beneficial effects of microorganisms on plants. Multiple advanced '-omics' technologies have enabled us to gain insights into the structure and function of plant-associated microbes. In this review, we first focus on microbe-mediated plant salt tolerance, in particular on the physiological and molecular mechanisms underlying root-microbe symbiosis. Unfortunately, when introducing such microbes as single strains to soils, they are often ineffective in improving plant growth and stress tolerance, largely due to competition with native soil microbial communities and limited colonization efficiency. Rapid progress in rhizosphere microbiome research has revived the belief that plants may benefit more from association with interacting, diverse microbial communities (microbiome) than from individual members in a community. Understanding how a microbiome assembles in the continuous compartments (endosphere, rhizoplane, and rhizosphere) will assist in predicting a subset of core or minimal microbiome and thus facilitate synthetic re-construction of microbial communities and their functional complementarity and synergistic effects. These developments will open a new avenue for capitalizing on the cultivable microbiome to strengthen plant salt tolerance and thus to refine agricultural practices and production under saline conditions.
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46
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Functions, mechanisms and regulation of endophytic and epiphytic microbial communities of plants. Symbiosis 2015. [DOI: 10.1007/s13199-015-0350-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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47
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Gond SK, Bergen MS, Torres MS, White JF, Kharwar RN. Effect of bacterial endophyte on expression of defense genes in Indian popcorn against Fusarium moniliforme. Symbiosis 2015. [DOI: 10.1007/s13199-015-0348-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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