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Dai Y, Yang F, Zhang L, Xu Z, Fan X, Tian Y, Wang T. Wheat-associated microbiota and their correlation with stripe rust reaction. J Appl Microbiol 2019; 128:544-555. [PMID: 31606919 DOI: 10.1111/jam.14486] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/17/2019] [Accepted: 10/09/2019] [Indexed: 12/12/2022]
Abstract
AIMS This study was aimed at revealing the composition of microbiota in leaves, roots and rhizosphere soil of wheat plants that are resistant or susceptible to stripe rust, one of the most widely destructive leaf diseases in wheat production. METHODS AND RESULTS A total of 36 wheat plants that showed resistant or susceptible reactions to stripe rust were sampled. Three compartments of each plant including leaves, roots and rhizosphere soil were used for whole-genomic DNA extraction and the DNA samples were subjected to high-throughput 16S rRNA gene sequencing. A total of 2885 operational taxonomic units (OTUs) were revealed from the sequencing, and they mainly distributed in the phylum of Proteobacteria. Twenty-nine OTUs formed the core microbiota of wheat plants. The differences between above- and below-ground environments could explain most of the dissimilarity of wheat-associated microbial communities. Therefore, those microbes that were able to adapt to the above-ground (leaf) environment might be more important resources for biocontrol agents against stripe rust, and they could be from genera Hymenobacter, Flavobacterium, Chitinophage, Flavisolibacter, Niastella, Mucilaginibacter, Pedobacter, Aquincola, Massilia, Citrobacter, Cronobacter, Ewingella, Acinetobacter and Pseudomonas. No matter the microbial taxa were significantly selected by the resistant or susceptible wheat plants, they contained the members with plant growth promoting (PGP) features and could be used as potential biocontrol agents to reduce stripe rust damage. CONCLUSIONS The core microbiota associated with wheat plants and microbial taxa that were significantly correlated with reactions to stripe rust were identified in this study. SIGNIFICANCE AND IMPACT OF THE STUDY Few studies had been done on the microbiota associated with wheat so far. Our study will not only provide fundamental knowledge about the composition of wheat-associated microbiota but also reveal the microbial taxa that have the potential to be integrated into the strategy of stripe rust management.
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Affiliation(s)
- Y Dai
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China
| | - F Yang
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - L Zhang
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Z Xu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China
| | - X Fan
- Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China
| | - Y Tian
- Laboratory of Leather Chemistry and Engineering, College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu, Sichuan, China
| | - T Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Sichuan, China
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202
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Padda KP, Puri A, Chanway C. Endophytic nitrogen fixation – a possible ‘hidden’ source of nitrogen for lodgepole pine trees growing at unreclaimed gravel mining sites. FEMS Microbiol Ecol 2019; 95:5606785. [DOI: 10.1093/femsec/fiz172] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/23/2019] [Indexed: 01/19/2023] Open
Abstract
ABSTRACTLodgepole pine (Pinus contorta var. latifolia) trees have been thriving on unreclaimed gravel mining sites in British Columbia, Canada, with tissue nitrogen-content and growth-rate unaffected by extremely low soil nitrogen-levels. This indicates that pine trees could be accessing a hidden nitrogen source to fulfill their nitrogen requirements – possibly via endophytic nitrogen-fixation. Endophytic bacteria originally isolated from native pine trees growing at gravel sites were selected (n = 14) for in vitro nitrogen-fixation assays and a year long greenhouse study to test the overall hypothesis that naturally occurring endophytic nitrogen-fixing bacteria sustain pine tree growth under nitrogen-limited conditions. Each of the 14 bacteria colonized the internal tissues of pine trees in the greenhouse study and fixed significant amounts of nitrogen from atmosphere (23%–53%) after one year as estimated through 15N isotope dilution assay. Bacterial inoculation also significantly enhanced the length (31%–64%) and biomass (100%–311%) of pine seedlings as compared to the non-inoculated control treatment. In addition, presence of the nifH gene was confirmed in all 14 bacteria. Our results support the possibility that pine trees associate with nitrogen-fixing bacteria, capable of endophytic colonization, to survive at unreclaimed gravel mining pits and this association could potentially be utilized for effective reclamation of highly disturbed sites in a sustainable manner.
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Affiliation(s)
- Kiran Preet Padda
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Akshit Puri
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Chanway
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
- Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia, Canada
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203
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Bacterial and Fungal Endophytes: Tiny Giants with Immense Beneficial Potential for Plant Growth and Sustainable Agricultural Productivity. Microorganisms 2019; 7:microorganisms7110481. [PMID: 31652843 PMCID: PMC6921065 DOI: 10.3390/microorganisms7110481] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 11/17/2022] Open
Abstract
The conventional means of achieving enhanced agricultural productivity are not ecologically balanced and sustainable. The excessive use of synthetic agrochemicals, declining soil nutrients, and water-use issues, amongst others, are threats to the ecosystem. Additionally, environmental degradation and an increasing global population that will reach 9 billion by 2030 are further considerations. These issues mean a decline in the volume of food resources available to feed the world. Therefore, sustainably increasing agricultural productivity is a necessity for restoring soil fertility, feeding the populace, and improving the ecosystem. A way to achieve this is by using eco-friendly microbial inoculants. Endophytes inhabit the tissues of plants asymptomatically without causing adverse effects. Bacterial and fungal endophytes benefit plants by promoting growth, suppressing pathogens, and improving the stress tolerance and immunity of plants. Despite this vital role played by endophytes in their interactions with host plants, there is still a paucity of relevant review data. More importantly, the prospective use of endophytes as an alternative to synthetic agrochemicals to ensure agro-ecological crop productivity has not been well reviewed in the literature. Therefore, this review sought to highlight the potential use of endophytic microbial resources to achieve enhancements in agro-food system crops in a sustainable manner.
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204
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Kushwaha P, Kashyap PL, Srivastava AK, Tiwari RK. Plant growth promoting and antifungal activity in endophytic Bacillus strains from pearl millet (Pennisetum glaucum). Braz J Microbiol 2019; 51:229-241. [PMID: 31642002 DOI: 10.1007/s42770-019-00172-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/03/2019] [Indexed: 12/13/2022] Open
Abstract
Bacterial endophytes are well known inhabitants of living plant system and perform important assignments in maintaining plant growth and health. Currently, limited reports are available on the endophytes of pearl millet (Pennisetum glaucum) reflecting antagonistic and plant growth promoting (PGP) attributes. Therefore, the major objectives of current investigation were to identify antagonistic strains of endophytic Bacillus from pearl millet and further illustrate their PGP capabilities. In this study, 19 endophytic Bacillus strains (EPP5, EPP21, EPP30, EPP32, EPP35, EPP42, EPP49, EPP55, EPP62, EPP65, EPP70, EPP71, EPP74, EPP78, EPP83, EPP86, EPP93, EPP100, and EPP102) displaying antagonistic activity towards Rhizoctonia solani (RS), Sclerotium rolfsii (SR), and Fusarium solani (FS) were isolated from different sections (root, leaf, stem, and root) of pearl millet. Phenotypic (shape, colony, gram staining reaction, endospore formation, and motility) and biochemical features (catalase, oxidase, citrate, gelatinase, urease, Voges Proskauer's, methyl red, indole, and nitrate reduction), along with the similarly comparison of 16S rRNA gene sequence with type strains identified eight antagonistic endophyhtes as B. amyloliquefaciens (EPP35, EPP 42, EPP62, and EPP 102), Bacillus subtilis subsp. subtilis (EPP65), and Bacillus cereus (EPP5, EPP71, and EPP74). The production of indole acetic acid and siderophores was varied among the isolated endophytes. Besides displaying enzymatic activities, these isolates varied in solubilizing capabilities of phosphate, potassium, and zinc. The presence of three antimicrobial peptide genes (ituD, bmyC, and srfA) also confirmed their antifungal nature. Further, single treatment of three promising strains (EPP5, EPP62, and EPP65) offered protection ranging from 35.68 to 45.74% under greenhouse conditions. However, microbial consortium (EPP5+ EPP62 + EPP65) provided the highest protection (71.96%) against root rot and wilt infection with significant increase in plant biomass. Overall, the current study indicated that pearl millet plant harbors various species of endophytic Bacillus that possess excellent biocontrol and growth promotion activities.
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Affiliation(s)
- Prity Kushwaha
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, 275103, India
- AMITY Institute of Biotechnology, AMITY University Lucknow Campus, Lucknow, Uttar Pradesh, 226028, India
| | - Prem Lal Kashyap
- ICAR- Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, India.
| | - Alok Kumar Srivastava
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, 275103, India
| | - Rajesh Kumar Tiwari
- AMITY Institute of Biotechnology, AMITY University Lucknow Campus, Lucknow, Uttar Pradesh, 226028, India
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Ashitha A, Midhun S, Sunil M, Nithin T, Radhakrishnan E, Mathew J. Bacterial endophytes from Artemisia nilagirica (Clarke) Pamp., with antibacterial efficacy against human pathogens. Microb Pathog 2019; 135:103624. [DOI: 10.1016/j.micpath.2019.103624] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/03/2019] [Accepted: 07/16/2019] [Indexed: 11/17/2022]
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White JF, Kingsley KL, Zhang Q, Verma R, Obi N, Dvinskikh S, Elmore MT, Verma SK, Gond SK, Kowalski KP. Review: Endophytic microbes and their potential applications in crop management. PEST MANAGEMENT SCIENCE 2019; 75:2558-2565. [PMID: 31228333 PMCID: PMC6771842 DOI: 10.1002/ps.5527] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 05/06/2023]
Abstract
Endophytes are microbes (mostly bacteria and fungi) present asymptomatically in plants. Endophytic microbes are often functional in that they may carry nutrients from the soil into plants, modulate plant development, increase stress tolerance of plants, suppress virulence in pathogens, increase disease resistance in plants, and suppress development of competitor plant species. Endophytic microbes have been shown to: (i) obtain nutrients in soils and transfer nutrients to plants in the rhizophagy cycle and other nutrient-transfer symbioses; (ii) increase plant growth and development; (iii) reduce oxidative stress of hosts; (iv) protect plants from disease; (v) deter feeding by herbivores; and (vi) suppress growth of competitor plant species. Because of the effective functions of endophytic microbes, we suggest that endophytic microbes may significantly reduce use of agrochemicals (fertilizers, fungicides, insecticides, and herbicides) in the cultivation of crop plants. The loss of endophytic microbes from crop plants during domestication and long-term cultivation could be remedied by transfer of endophytes from wild relatives of crops to crop species. Increasing atmospheric carbon dioxide levels could reduce the efficiency of the rhizophagy cycle due to repression of reactive oxygen used to extract nutrients from microbes in roots. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- James F White
- Department of Plant BiologyRutgers UniversityNew BrunswickNJUSA
| | | | - Qiuwei Zhang
- Department of Plant BiologyRutgers UniversityNew BrunswickNJUSA
| | - Rajan Verma
- Department of Plant BiologyRutgers UniversityNew BrunswickNJUSA
| | - Nkolika Obi
- Department of Plant BiologyRutgers UniversityNew BrunswickNJUSA
| | - Sofia Dvinskikh
- Department of Plant BiologyRutgers UniversityNew BrunswickNJUSA
| | | | - Satish K Verma
- Centre of Advanced Study in BotanyBanaras Hindu UniversityVaranasiIndia
| | - Surendra K Gond
- Centre of Advanced Study in BotanyBanaras Hindu UniversityVaranasiIndia
| | - Kurt P Kowalski
- U.S. Geological SurveyGreat Lakes Science CenterClevelandOHUSA
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Hartmann A, Fischer D, Kinzel L, Chowdhury SP, Hofmann A, Baldani JI, Rothballer M. Assessment of the structural and functional diversities of plant microbiota: Achievements and challenges - A review. J Adv Res 2019; 19:3-13. [PMID: 31341665 PMCID: PMC6629839 DOI: 10.1016/j.jare.2019.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 12/28/2022] Open
Abstract
Analyses of the spatial localization and the functions of bacteria in host plant habitats through in situ identification by immunological and molecular genetic techniques combined with high resolving microscopic tools and 3D-image analysis contributed substantially to a better understanding of the functional interplay of the microbiota in plants. Among the molecular genetic methods, 16S-rRNA genes were of central importance to reconstruct the phylogeny of newly isolated bacteria and to localize them in situ. However, they usually do not allow resolution for phylogenetic affiliations below genus level. Especially, the separation of opportunistic human pathogens from plant beneficial strains, currently allocated to the same species, needs genome-based resolving techniques. Whole bacterial genome sequences allow to discriminate phylogenetically closely related strains. In addition, complete genome sequences enable strain-specific monitoring for biotechnologically relevant strains. In this mini-review we present high resolving approaches for analysis of the composition and key functions of plant microbiota, focusing on interactions of diazotrophic plant growth promoting bacteria, like Azospirillum brasilense, with non-legume host plants. Combining high resolving microscopic analyses with specific immunological detection methods and molecular genetic tools, including especially transcriptome analyses of both the bacterial and plant partners, enables new insights into key traits of beneficial bacteria-plant interactions in holobiontic systems.
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Affiliation(s)
- Anton Hartmann
- Ludwig-Maximilians-Universität (LMU) München, Faculty of Biology, Host-Microbe interactions, Großhaderner Str. 2-4, D-82152 Martinsried, Germany
| | - Doreen Fischer
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Munich, Germany
| | - Linda Kinzel
- Research Unit Microbe-Plant Interactions, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Munich, Germany
| | - Soumitra Paul Chowdhury
- Institute of Network Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Munich, Germany
| | - Andreas Hofmann
- EMBRAPA-Agrobiologia, Br 465, Km 07, Seropédica–RJ–CEP 23891-000, Brazil
| | - Jose Ivo Baldani
- EMBRAPA-Agrobiologia, Br 465, Km 07, Seropédica–RJ–CEP 23891-000, Brazil
| | - Michael Rothballer
- Institute of Network Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Munich, Germany
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208
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Cruz Barrera M, Jakobs-Schoenwandt D, Gómez MI, Becker M, Patel AV, Ruppel S. Salt stress and hydroxyectoine enhance phosphate solubilisation and plant colonisation capacity of Kosakonia radicincitans. J Adv Res 2019; 19:91-97. [PMID: 31341674 PMCID: PMC6629720 DOI: 10.1016/j.jare.2019.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/15/2019] [Accepted: 03/25/2019] [Indexed: 11/24/2022] Open
Abstract
Gram-negative bacterial endophytes have attracted research interest caused by their advantageous over epiphytic bacteria in plant nutrition and protection. However, research on these typically Gram-negative endophytes has deficiencies concerning the role of cultivation and pre-formulation strategies on further plant colonisation capabilities. Besides, the influence of cultivation conditions and osmotic stress within bacterial endophytes on their phosphate solubilising ability has not yet been addressed. By pre-conditioning cells with an osmoadaptation and a hydroxyectoine accumulation approach, this research aimed at enhancing the capability of the plant growth promoting bacterium Kosakonia radicincitans strain DSM 16656T to both solubilise phosphate and colonise plant seedlings. The results showed that halotolerant bacterial phenotypes increased the root-colonising capability by approximately 3-fold and presented growth-promoting effects in radish plants. Interestingly, findings also demonstrated that salt stress in the culture media along with the accumulation of hydroxyectoine led to an increase in the in vitro phosphate-solubilising ability by affecting the production of acid phosphatases, from 1.24 to 3.34 U mg-1 for non-salt stressed cells and hydroxyectoine-added cells respectively. Thus, this approach provides a useful knowledge upon which the salt stress and compatible solutes in bacteria endophytes can confer phenotypic adaptations to support the eco-physiological performance concerning phosphate-solubilising abilities and endosphere establishment.
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Affiliation(s)
- Mauricio Cruz Barrera
- Corporación Colombiana de Investigación Agropecuaria (Agrosavia), Mosquera, Colombia. Km 14, Bogotá-Mosquera, Colombia
| | - Desirée Jakobs-Schoenwandt
- Bielefeld University of Applied Sciences, WG Fermentation and Formulation of Biologicals and Chemicals, Department of Engineering Sciences and Mathematics, Bielefeld, Germany
| | - Martha Isabel Gómez
- Corporación Colombiana de Investigación Agropecuaria (Agrosavia), Mosquera, Colombia. Km 14, Bogotá-Mosquera, Colombia
| | - Matthias Becker
- Leibniz-Institute of Vegetable and Ornamental Crops, Grossbeeren, Germany
| | - Anant V. Patel
- Bielefeld University of Applied Sciences, WG Fermentation and Formulation of Biologicals and Chemicals, Department of Engineering Sciences and Mathematics, Bielefeld, Germany
| | - Silke Ruppel
- Leibniz-Institute of Vegetable and Ornamental Crops, Grossbeeren, Germany
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Andreozzi A, Prieto P, Mercado-Blanco J, Monaco S, Zampieri E, Romano S, Valè G, Defez R, Bianco C. Efficient colonization of the endophytes Herbaspirillum huttiense RCA24 and Enterobacter cloacae RCA25 influences the physiological parameters of Oryza sativa L. cv. Baldo rice. Environ Microbiol 2019; 21:3489-3504. [PMID: 31106946 DOI: 10.1111/1462-2920.14688] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 11/26/2022]
Abstract
Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase activity and production of siderophores and phytohormones, can be assessed as plant growth promotion traits. Our aim was to evaluate the effects of nitrogen fixing and indole-3-acetic acid (IAA) producing endophytes in two Oryza sativa cultivars (Baldo and Vialone Nano). Three bacteria, Herbaspirillum huttiense RCA24, Enterobacter asburiae RCA23 and Staphylococcus sp. 377, producing different IAA levels, were tested for their ability to enhance nifH gene expression and nitrogenase activity in Enterobacter cloacae RCA25. Results showed that H. huttiense RCA24 performed best. Improvement in nitrogen fixation and changes in physiological parameters such as chlorophyll, nitrogen content and shoot dry weight were observed for plants co-inoculated with strains RCA25 and RCA24 in a 10:1 ratio. Based on confocal laser scanning microscopy analysis, strain RCA24 was the best colonizer of the root interior and the only IAA producer located in the same root niche occupied by RCA25 cells. This work shows that the choice of a bio-inoculum having the right composition is one of the key aspects to be considered for the inoculation of a specific host plant cultivar with microbial consortia.
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Affiliation(s)
- Anna Andreozzi
- Institute of Biosciences and BioResources, via P. Castellino 111, 80131 Naples, Italy
| | - Pilar Prieto
- Departamento de Mejora Genética, Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Campus 'Alameda del Obispo', Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Jesús Mercado-Blanco
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Campus 'Alameda del Obispo', Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Stefano Monaco
- CREA - CI, Research Centre for Cereal and Industrial Crops, 13100, Vercelli, Italy
| | - Elisa Zampieri
- CREA - CI, Research Centre for Cereal and Industrial Crops, 13100, Vercelli, Italy
| | - Silvia Romano
- Institute of Biosciences and BioResources, via P. Castellino 111, 80131 Naples, Italy
| | - Gianpiero Valè
- DiSIT, Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Piazza San Eusebio 5, I-13100 Vercelli, Italy
| | - Roberto Defez
- Institute of Biosciences and BioResources, via P. Castellino 111, 80131 Naples, Italy
| | - Carmen Bianco
- Institute of Biosciences and BioResources, via P. Castellino 111, 80131 Naples, Italy
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Inácio MC, Paz TA, Pereira AMS, Furlan M. Maytenin Plays a Special Role in the Regulation of the Endophytic Bacillus megaterium in Peritassa campestris Adventitious Roots. J Chem Ecol 2019; 45:789-797. [DOI: 10.1007/s10886-019-01096-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/18/2019] [Accepted: 08/05/2019] [Indexed: 01/15/2023]
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Plant Probiotic Bacterial Endophyte, Alcaligenes faecalis, Modulates Plant Growth and Forskolin Biosynthesis in Coleus forskohlii. Probiotics Antimicrob Proteins 2019; 12:481-493. [DOI: 10.1007/s12602-019-09582-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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212
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Ben Slama H, Triki MA, Chenari Bouket A, Ben Mefteh F, Alenezi FN, Luptakova L, Cherif-Silini H, Vallat A, Oszako T, Gharsallah N, Belbahri L. Screening of the High-Rhizosphere Competent Limoniastrum monopetalum' Culturable Endophyte Microbiota Allows the Recovery of Multifaceted and Versatile Biocontrol Agents. Microorganisms 2019; 7:microorganisms7080249. [PMID: 31405010 PMCID: PMC6723025 DOI: 10.3390/microorganisms7080249] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 11/18/2022] Open
Abstract
Halophyte Limoniastrum monopetalum, an evergreen shrub inhabiting the Mediterranean region, has well-documented phytoremediation potential for metal removal from polluted sites. It is also considered to be a medicinal halophyte with potent activity against plant pathogens. Therefore, L. monopetalum may be a suitable candidate for isolating endophytic microbiota members that provide plant growth promotion (PGP) and resistance to abiotic stresses. Selected for biocontrol abilities, these endophytes may represent multifaceted and versatile biocontrol agents, combining pathogen biocontrol in addition to PGP and plant protection against abiotic stresses. In this study 117 root culturable bacterial endophytes, including Gram-positive (Bacillus and Brevibacillus), Gram-negative (Proteus, Providencia, Serratia, Pantoea, Klebsiella, Enterobacter and Pectobacterium) and actinomycete Nocardiopsis genera have been recovered from L. monopetalum. The collection exhibited high levels of biocontrol abilities against bacterial (Agrobacterium tumefaciens MAT2 and Pectobacterium carotovorum MAT3) and fungal (Alternaria alternata XSZJY-1, Rhizoctonia bataticola MAT1 and Fusarium oxysporum f. sp. radicis lycopersici FORL) pathogens. Several bacteria also showed PGP capacity and resistance to antibiotics and metals. A highly promising candidate Bacillus licheniformis LMRE 36 with high PGP, biocontrol, metal and antibiotic, resistance was subsequently tested in planta (potato and olive trees) for biocontrol of a collection of 14 highly damaging Fusarium species. LMRE 36 proved very effective against the collection in both species and against an emerging Fusarium sp. threatening olive trees culture in nurseries. These findings provide a demonstration of our pyramiding strategy. Our strategy was effective in combining desirable traits in biocontrol agents towards broad-spectrum resistance against pathogens and protection of crops from abiotic stresses. Stacking multiple desirable traits into a single biocontrol agent is achieved by first, careful selection of a host for endophytic microbiota recovery; second, stringent in vitro selection of candidates from the collection; and third, application of the selected biocontrol agents in planta experiments. That pyramiding strategy could be successfully used to mitigate effects of diverse biotic and abiotic stresses on plant growth and productivity. It is anticipated that the strategy will provide a new generation of biocontrol agents by targeting the microbiota of plants in hostile environments.
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Affiliation(s)
- Houda Ben Slama
- NextBiotech, 98 Rue Ali Belhouane, Agareb 3030, Tunisia
- Institut de l'Olivier Sfax, Sfax 3000, Tunisia
| | | | - Ali Chenari Bouket
- Plant Protection Research Department, East Azarbaijan Agricultural and Natural Resources Research and Education Center, AREEO, 5355179854 Tabriz, Iran
| | - Fedia Ben Mefteh
- Faculty of Science, B.P. 1171, 3000, University of Sfax, Sfax 3029, Tunisia
| | - Faizah N Alenezi
- NextBiotech, 98 Rue Ali Belhouane, Agareb 3030, Tunisia
- Department of Environmental Technology Management, College of Life Sciences, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
| | - Lenka Luptakova
- Department of Biology and Genetics, Institute of Biology, Zoology and Radiobiology, University of Veterinary Medicine and Pharmacy, 04181 Kosice, Slovakia
| | - Hafsa Cherif-Silini
- Laboratory of Applied Microbiology, Department of Microbiology, Faculty of Natural and Life Sciences, University Ferhat Abbas of Setif, 19000 Setif, Algeria
| | - Armelle Vallat
- Neuchatel Platform of Analytical Chemistry, Institute of Chemistry, University of Neuchatel, 2000 Neuchatel, Switzerland
| | - Tomasz Oszako
- Department of Forest Protection, Forest Research Institute, 05-090 Raszyn, Poland
| | - Neji Gharsallah
- Faculty of Science, B.P. 1171, 3000, University of Sfax, Sfax 3029, Tunisia
| | - Lassaad Belbahri
- NextBiotech, 98 Rue Ali Belhouane, Agareb 3030, Tunisia.
- Laboratory of Soil Biology, University of Neuchatel, 2000 Neuchatel, Switzerland.
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Ullah A, Nisar M, Ali H, Hazrat A, Hayat K, Keerio AA, Ihsan M, Laiq M, Ullah S, Fahad S, Khan A, Khan AH, Akbar A, Yang X. Drought tolerance improvement in plants: an endophytic bacterial approach. Appl Microbiol Biotechnol 2019; 103:7385-7397. [PMID: 31375881 DOI: 10.1007/s00253-019-10045-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/17/2019] [Accepted: 07/23/2019] [Indexed: 12/31/2022]
Abstract
Climate change is a crucial issue among the serious emerging problems which got a global attention in the last few decades. With the climate change, worldwide crop production has been seriously affected by drought stress. In this regard, various technologies including traditional breeding and genetic engineering are used to cope with drought stress. However, the interactions between plants and endophytic bacteria emerged as an interesting era of knowledge that can be used for novel agriculture practices. Endophytic bacteria which survive within plant tissues are among the most appropriate technologies improving plant growth and yield under drought conditions. These endophytic bacteria live within plant tissues and release various phytochemicals that assist plant to withstand in harsh environmental conditions, i.e., drought stress. Their plant growth-promoting characteristics include nitrogen fixation, phosphate solubilization, mineral uptake, and the production of siderophore, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and various phytohormones. These plant growth promoting characteristics of endophytic bacteria improve root length and density, which lead to the enhance drought tolerance. In addition, plant-endophytic bacteria assist plant to withstand against drought stress by producing drought-tolerant substances, for instance, abscisic acid, indole-3-acetic acid, ACC deaminase, and various volatile compounds. Indirectly, endophytic bacteria also improve osmotic adjustment, relative water content, and antioxidant activity of inoculated plants. Altogether, these bacterial-mediated drought tolerance and plant growth-promoting processes continue even under severe drought conditions which lead to enhanced plant growth promotion and yield. The present review highlights a natural and environment-friendly strategy in the form of drought-tolerant and plant growth-promoting endophytic bacteria to improve drought tolerance in plants.
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Affiliation(s)
- Abid Ullah
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan. .,National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
| | - Mohammad Nisar
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Hazrat Ali
- Department of Zoology, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Ali Hazrat
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Kashif Hayat
- Key Laboratory of Urban Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ayaz Ali Keerio
- Department of Plant Breeding and Genetics, Faculty of Crop Production, Sindh Agriculture University, Tando Jam, Hyderabad, Sindh, Pakistan
| | - Muhammad Ihsan
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Muhammad Laiq
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Sana Ullah
- Department of Botany, University of Malakand, Chakdara Dir Lower, Khyber Pakhtunkhwa, 18800, Pakistan
| | - Shah Fahad
- Department of Agriculture, University of Swabi, Swabi, Khyber Pakhtunkhwa, Pakistan
| | - Aziz Khan
- Key Laboratory of Plant Genetic and Breeding, College of Agriculture, Guanxi University, Nanning, 530005, Guanxi, China
| | - Aamir Hamid Khan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Adnan Akbar
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Xiyan Yang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
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214
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Maheshwari R, Bhutani N, Bhardwaj A, Suneja P. Functional diversity of cultivable endophytes from Cicer arietinum and Pisum sativum: Bioprospecting their plant growth potential. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101229] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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215
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Saleh D, Jarry J, Rani M, Aliferis K, Seguin P, Jabaji S. Diversity, distribution and multi‐functional attributes of bacterial communities associated with the rhizosphere and endosphere of timothy (Phleum pratenseL.). J Appl Microbiol 2019; 127:794-811. [DOI: 10.1111/jam.14334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 05/09/2019] [Accepted: 05/15/2019] [Indexed: 11/29/2022]
Affiliation(s)
- D. Saleh
- Department of Plant Science Department, Faculty of Agricultural and Environmental Sciences Macdonald Campus of McGill University Ste‐Anne‐De Bellevue QC Canada
| | - J. Jarry
- Department of Plant Science Department, Faculty of Agricultural and Environmental Sciences Macdonald Campus of McGill University Ste‐Anne‐De Bellevue QC Canada
| | - M. Rani
- Department of Plant Science Department, Faculty of Agricultural and Environmental Sciences Macdonald Campus of McGill University Ste‐Anne‐De Bellevue QC Canada
| | - K.A. Aliferis
- Laboratory of Pesticide Science Agricultural University of Athens Athens Greece
| | - P. Seguin
- Department of Plant Science Department, Faculty of Agricultural and Environmental Sciences Macdonald Campus of McGill University Ste‐Anne‐De Bellevue QC Canada
| | - S.H. Jabaji
- Department of Plant Science Department, Faculty of Agricultural and Environmental Sciences Macdonald Campus of McGill University Ste‐Anne‐De Bellevue QC Canada
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216
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Aghai MM, Khan Z, Joseph MR, Stoda AM, Sher AW, Ettl GJ, Doty SL. The Effect of Microbial Endophyte Consortia on Pseudotsuga menziesii and Thuja plicata Survival, Growth, and Physiology Across Edaphic Gradients. Front Microbiol 2019; 10:1353. [PMID: 31275276 PMCID: PMC6591459 DOI: 10.3389/fmicb.2019.01353] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/31/2019] [Indexed: 11/17/2022] Open
Abstract
Increased frequency of droughts and degraded edaphic conditions decreases the success of many reforestation efforts in the Pacific Northwest. Microbial endophyte consortia have been demonstrated to contribute to plant growth promotion and protection from abiotic and biotic stresses – specifically drought conditions – across a number of food crops but for limited tree species. Our research aimed to investigate the potential to improve establishment of economically and ecologically important conifers through a series of in situ field trials and ex situ simulations. Microbial endophyte consortia from Salicaceae, previously shown to confer drought tolerance, and conifer endophyte strains with potentially symbiotic traits were selected for trials with Douglas-fir (Pseudotsuga menziesii) and western redcedar (Thuja plicata). Reductive experimentation was used to subject seedlings to a spectrum of simulated drought levels or presence/absence of fertilizer, testing hypotheses that endophyte consortia impart improved drought resistance and growth promotion, respectively. Inoculation from Salicaceae consortia significantly (p ≤ 0.05) improved survival among seedlings of both species subject to increasing drought stress, with T. plicata seedlings surviving at twofold higher rates in extreme drought conditions. Both species demonstrated improved growth 540 days after inoculation of seed with conifer derived consortia. In the carefully controlled greenhouse experiments with both species, seedling Fv/Fm and SPAD values remained significantly (p ≤ 0.05) more stable in inoculated treatment groups as stress increased. Our findings confirm that multi-strain consortia may be applied as seed or field amendment to conifers, and the approach is efficient in garnering a positive growth response and can mitigate abiotic stressors.
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Affiliation(s)
- Matthew M Aghai
- UW Center for Sustainable Forestry at Pack Forest, Eatonville, WA, United States.,School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Zareen Khan
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Matthew R Joseph
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Aubrey M Stoda
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Andrew W Sher
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Gregory J Ettl
- UW Center for Sustainable Forestry at Pack Forest, Eatonville, WA, United States.,School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Sharon L Doty
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
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217
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Shaik SP, Thomas P. In Vitro Activation of Seed-Transmitted Cultivation-Recalcitrant Endophytic Bacteria in Tomato and Host⁻Endophyte Mutualism. Microorganisms 2019; 7:microorganisms7050132. [PMID: 31091826 PMCID: PMC6560416 DOI: 10.3390/microorganisms7050132] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 12/24/2022] Open
Abstract
This study was aimed at exploring seed transmission of endophytic bacteria in tomato utilizing aseptic in vitro conditions. Cultivation-based studies were undertaken on two tomato cultivars “Arka Vikas” and “Arka Abha” employing surface sterilized seeds, aseptically germinated seeds and in vitro grown seedlings at different stages. Bacillus sp. appeared primarily as seed externally-associated bacteria. Tissue homogenate from extensively surface-sterilized seeds, day-3 germinating seeds, or 10-day in vitro seedlings did not show any cultivable bacteria on two bacteriological media. Indexing of 4-week old healthy seedlings with seed-coat removal following seed germination showed bacterial association in 50–75% seedlings yielding 106–107 cfu g−1 tissues. Four endophytic bacteria appeared common to both cultivars (Kosakonia, Ralstonia, Sphingomonas, Sphingobium spp.) with three additional species in “Arka Abha”. The bacterial strains showed a manifold increase in growth with host-tissue-extract supplementation. Seed inoculations with single-isolates stimulated germination or enhanced the seedling growth coupled with the activation of additional endophytic bacteria. In vitro seedlings upon recurrent medium-indexing over eight weeks showed gradual emergence of endophytic bacteria. The study reveals the seed internal colonization by different bacterial endophytes in a cultivation-recalcitrant form, their activation to cultivable state during seedling growth and transmission to seedlings with mutualistic effects.
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Affiliation(s)
- Sadiq Pasha Shaik
- Division of Biotechnology, Endophytic and Molecular Microbiology Laboratory, ICAR-Indian Institute of Horticultural Research, Hessaraghatta Lake, Bengaluru 560089, India.
| | - Pious Thomas
- Division of Biotechnology, Endophytic and Molecular Microbiology Laboratory, ICAR-Indian Institute of Horticultural Research, Hessaraghatta Lake, Bengaluru 560089, India.
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218
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Defining the Genetic Basis of Plant⁻Endophytic Bacteria Interactions. Int J Mol Sci 2019; 20:ijms20081947. [PMID: 31010043 PMCID: PMC6515357 DOI: 10.3390/ijms20081947] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 01/17/2023] Open
Abstract
Endophytic bacteria, which interact closely with their host, are an essential part of the plant microbiome. These interactions enhance plant tolerance to environmental changes as well as promote plant growth, thus they have become attractive targets for increasing crop production. Numerous studies have aimed to characterise how endophytic bacteria infect and colonise their hosts as well as conferring important traits to the plant. In this review, we summarise the current knowledge regarding endophytic colonisation and focus on the insights that have been obtained from the mutants of bacteria and plants as well as ‘omic analyses. These show how endophytic bacteria produce various molecules and have a range of activities related to chemotaxis, motility, adhesion, bacterial cell wall properties, secretion, regulating transcription and utilising a substrate in order to establish a successful interaction. Colonisation is mediated by plant receptors and is regulated by the signalling that is connected with phytohormones such as auxin and jasmonic (JA) and salicylic acids (SA). We also highlight changes in the expression of small RNAs and modifications of the cell wall properties. Moreover, in order to exploit the beneficial plant-endophytic bacteria interactions in agriculture successfully, we show that the key aspects that govern successful interactions remain to be defined.
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219
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Insight into the Bacterial Endophytic Communities of Peach Cultivars Related to Crown Gall Disease Resistance. Appl Environ Microbiol 2019; 85:AEM.02931-18. [PMID: 30824451 DOI: 10.1128/aem.02931-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/22/2019] [Indexed: 11/20/2022] Open
Abstract
Crown gall disease caused by Agrobacterium tumefaciens severely impacts the production of peach and other fruit trees. Several peach cultivars are partially resistant to A. tumefaciens, but little is known about the roles of endophytic microbiota in disease resistance. In the present study, the endophytic bacterial communities of resistant and susceptible peach cultivars "Honggengansutao" and "Okinawa" were analyzed using universal 16S rRNA gene amplicon sequencing in parallel with the cultivation and characterization of bacterial isolates. A total of 1,357,088 high-quality sequences representing 3,160 distinct operational taxonomic units (OTUs; Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes) and 1,200 isolates of 20 genera and 305 distinct ribotypes were collected from peach roots and twigs. It was found that factors including plant developmental stage, cultivar, and A. tumefaciens invasion strongly influenced the peach endophytic communities. The community diversity of endophytic bacteria and the abundance of culturable bacteria were both higher in the roots of the resistant cultivar, particularly after inoculation. Strikingly, the pathogen antagonists Streptomyces and Pseudomonas in roots and Rhizobium in twigs were most frequently detected in resistant plants. Our results suggest that the higher abundance and diversity of endophytic bacteria and increased proportions of antagonistic bacteria might contribute to the natural defense of the resistant cultivar against A. tumefaciens This work reveals the relationships between endophytic bacteria and disease resistance in peach plants and provides important information for microbiome-based biocontrol of crown gall disease in fruit trees.IMPORTANCE Agrobacterium tumefaciens as the causal agent of peach crown gall disease can be controlled by planting resistant cultivars. This study profiles the endophytic bacteria in susceptible and resistant peach cultivars, advancing our understanding of the relationships between endophytic bacterial communities and peach crown gall disease, with potential implications for other complex microbiome-plant-pathogen interactions. The resistant cultivar may defend itself by increasing the diversity and abundance of beneficial endophytic bacteria. The antagonists identified among the genera Streptomyces, Pseudomonas, and Rhizobium may have application potential for biocontrol of crown gall disease in fruit trees.
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220
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Gentzel I, Giese L, Zhao W, Alonso AP, Mackey D. A Simple Method for Measuring Apoplast Hydration and Collecting Apoplast Contents. PLANT PHYSIOLOGY 2019; 179:1265-1272. [PMID: 30824565 PMCID: PMC6446764 DOI: 10.1104/pp.18.01076] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/21/2019] [Indexed: 05/23/2023]
Abstract
The plant leaf apoplast is a dynamic environment subject to a variety of both internal and external stimuli. In addition to being a conduit for water vapor and gas exchange involved in transpiration and photosynthesis, the apoplast also accumulates many nutrients transported from the soil as well as those produced through photosynthesis. The internal leaf also provides a protective environment for endophytic and pathogenic microbes alike. Given the diverse array of physiological processes occurring in the apoplast, it is expedient to develop methods to study its contents. Many established methods rely on vacuum infiltration of an apoplast wash solution followed by centrifugation. In this study, we describe a refined method optimized for maize (Zea mays) seedling leaves, which not only provides a simple procedure for obtaining apoplast fluid, but also allows direct calculation of apoplast hydration at the time of harvest for every sample. In addition, we describe an abbreviated method for estimating apoplast hydration if the full apoplast extraction is not necessary. Finally, we show the applicability of this optimized apoplast extraction procedure for plants infected with the maize pathogen Pantoea stewartii ssp stewartii, including the efficient isolation of bacteria previously residing in the apoplast. The approaches to establishing this method should make it generally applicable to other types of plants.
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Affiliation(s)
- Irene Gentzel
- Translational Plant Sciences Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Laura Giese
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
| | - Wanying Zhao
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
| | - Ana Paula Alonso
- BioDiscovery Institute, University of North Texas, Denton, Texas 76201
- Department of Biological Sciences, University of North Texas, Denton, Texas 76201
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210
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221
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Karmakar R, Bindiya S, Hariprasad P. Convergent evolution in bacteria from multiple origins under antibiotic and heavy metal stress, and endophytic conditions of host plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:858-867. [PMID: 30308860 DOI: 10.1016/j.scitotenv.2018.09.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/05/2018] [Accepted: 09/06/2018] [Indexed: 06/08/2023]
Abstract
The focus of this work is to study the convergent evolution in bacteria from multiple origins under antibiotic and heavy metal stress, and endophytic conditions of host plant cultivated on the Yamuna river bank. Forty-one endophytic bacteria (EB) were isolated from green leafy vegetables (GLV's) and were found to be resistant to a wide range of antibiotics (AB) and heavy metals (HM) tested. Further, they showed susceptibility to Quinolones group of antibiotics, and the HM, Cadmium, Chromium, and Mercury. Twenty-seven percent of these bacteria endowed with Class I integron. The probability of co-existence of HM resistance with β‑lactams was higher, whereas quinolones group of AB recorded lesser values. These EB owned a wide array of beneficial traits, through which they improved the plant health under HM and salt stress conditions. Bacterial identity revealed the association of both plant beneficial and human pathogenic bacteria as an endophyte with GLV's. Principal component analysis showed a pattern of convergent evolution irrespective of their origin. In conclusion, under the selection pressure of AB and HM, the susceptible EB population may reduce with time and the resistant native/introduced bacteria might survive. The vertical and horizontal gene transfer between introduced and native bacteria is the crucial factor in enhancing their fitness along with the host plant to survive under abiotic stress conditions.
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Affiliation(s)
- Ruma Karmakar
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, India
| | - Shefali Bindiya
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, India
| | - P Hariprasad
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, India.
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222
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Abstract
Endophytic bacteria form a symbiotic relation with plants and generally cause no harmful effects to the host plants. In a previous study, we isolated eight bacterial endophytes from sweet potato plants harvested in Salyan, Nepal. These endophytes showed plant growth-promoting properties as a mixed culture. In this study, we evaluated the ability of these strains to produce indole-3-acetic acid (IAA) and to fix nitrogen. Based on these results, we selected two strains, Klebsiella sp. Sal 1 and Enterobacter sp. Sal 3, and evaluated their ability to promote plant growth. IAA production activity peaked at 15–60 mg NH4NO3/L in plant-free medium. Similarly, acetylene reduction activity peaked at 0–6.25 mg NH4NO3/L. Both strains successfully colonized plants, promoted the growth of tomatoes, and induced phenotypes in plants consistent with IAA exposure. This suggests that these strains promote plant growth by producing IAA inside the plant, where nitrogen levels are expected to be low.
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223
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White JF, Kingsley KL, Verma SK, Kowalski KP. Rhizophagy Cycle: An Oxidative Process in Plants for Nutrient Extraction from Symbiotic Microbes. Microorganisms 2018; 6:microorganisms6030095. [PMID: 30227634 PMCID: PMC6164190 DOI: 10.3390/microorganisms6030095] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/01/2018] [Accepted: 09/05/2018] [Indexed: 12/20/2022] Open
Abstract
In this paper, we describe a mechanism for the transfer of nutrients from symbiotic microbes (bacteria and fungi) to host plant roots that we term the ‘rhizophagy cycle.’ In the rhizophagy cycle, microbes alternate between a root intracellular endophytic phase and a free-living soil phase. Microbes acquire soil nutrients in the free-living soil phase; nutrients are extracted through exposure to host-produced reactive oxygen in the intracellular endophytic phase. We conducted experiments on several seed-vectored microbes in several host species. We found that initially the symbiotic microbes grow on the rhizoplane in the exudate zone adjacent the root meristem. Microbes enter root tip meristem cells—locating within the periplasmic spaces between cell wall and plasma membrane. In the periplasmic spaces of root cells, microbes convert to wall-less protoplast forms. As root cells mature, microbes continue to be subjected to reactive oxygen (superoxide) produced by NADPH oxidases (NOX) on the root cell plasma membranes. Reactive oxygen degrades some of the intracellular microbes, also likely inducing electrolyte leakage from microbes—effectively extracting nutrients from microbes. Surviving bacteria in root epidermal cells trigger root hair elongation and as hairs elongate bacteria exit at the hair tips, reforming cell walls and cell shapes as microbes emerge into the rhizosphere where they may obtain additional nutrients. Precisely what nutrients are transferred through rhizophagy or how important this process is for nutrient acquisition is still unknown.
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Affiliation(s)
- James F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Kathryn L Kingsley
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Satish K Verma
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, UP 221005, India.
| | - Kurt P Kowalski
- U.S. Geological Survey, Great Lakes Science Center, 1451 Green Road, Ann Arbor, MI 48105-2807, USA.
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224
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Esmaeel Q, Miotto L, Rondeau M, Leclère V, Clément C, Jacquard C, Sanchez L, Barka EA. Paraburkholderia phytofirmans PsJN-Plants Interaction: From Perception to the Induced Mechanisms. Front Microbiol 2018; 9:2093. [PMID: 30214441 PMCID: PMC6125355 DOI: 10.3389/fmicb.2018.02093] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/16/2018] [Indexed: 12/13/2022] Open
Abstract
The use of plant-associated bacteria has received many scientific and economic attention as an effective and alternative method to reduce the chemical pesticides use in agriculture. The genus Burkholderia includes at least 90 species including pathogenic strains, plant pathogens, as well as plant beneficial species as those related to Paraburkholderia, which has been reported to be associated with plants and exerts a positive effect on plant growth and fitness. Paraburkholderia phytofirmans PsJN, a beneficial endophyte able to colonize a wide range of plants, is an established model for plant-associated endophytic bacteria. Indeed, in addition to its plant growth promoting ability, it can also induce plant resistance against biotic as well as abiotic stresses. Here, we summarized an inventory of knowledge on PsJN-plant interaction, from the perception to the resistance mechanisms induced in the plant by a way of the atypical colonization mode of this endophyte. We also have carried out an extensive genome analysis to identify all gene clusters which contribute to the adaptive mechanisms under different environments and partly explaining the high ecological competence of P. phytofirmans PsJN.
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Affiliation(s)
- Qassim Esmaeel
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Lidiane Miotto
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Marine Rondeau
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Valérie Leclère
- Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7394-ICV- Institut Charles Viollette, SFR Condorcet FR CNRS 3417, Lille, France
| | - Christophe Clément
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Cédric Jacquard
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Lisa Sanchez
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
| | - Essaid A Barka
- Unité de Résistance Induite et Bioprotection des Plantes EA 4707, SFR Condorcet FR CNRS 3417, University of Reims Champagne-Ardenne, Reims, France
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225
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Is Endophyte-Plant Co-Denitrification a Source of Nitrous Oxides Emission? —An Experimental Investigation with Soybean. AGRONOMY-BASEL 2018. [DOI: 10.3390/agronomy8070108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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226
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Doty SL. Symbiotic Plant-Bacterial Endospheric Interactions. Microorganisms 2018; 6:microorganisms6020028. [PMID: 29565291 PMCID: PMC6027310 DOI: 10.3390/microorganisms6020028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 03/15/2018] [Accepted: 03/20/2018] [Indexed: 01/29/2023] Open
Affiliation(s)
- Sharon Lafferty Doty
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195-2100, USA.
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227
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Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis. Microorganisms 2018. [PMID: 29518024 PMCID: PMC5874635 DOI: 10.3390/microorganisms6010021] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of genes for both compounds in the genome of SY1. HCN was detected in cultures of SY1. We conclude that microbes from non-cultivated plants may provide disease protection and promote growth of crop plants.
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Rho H, Van Epps V, Wegley N, Doty SL, Kim SH. Salicaceae Endophytes Modulate Stomatal Behavior and Increase Water Use Efficiency in Rice. FRONTIERS IN PLANT SCIENCE 2018; 9:188. [PMID: 29552021 PMCID: PMC5840156 DOI: 10.3389/fpls.2018.00188] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/31/2018] [Indexed: 05/18/2023]
Abstract
Bacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO2 enrichment and water deficit. Daytime stomatal conductance and stomatal density were lower in inoculated plants compared to controls. Leaf ABA concentrations increased with endophyte inoculation. As a result, transpirational water use decreased significantly with endophyte inoculation while biomass did not change or slightly increased. This response led to a significant increase in cumulative water use efficiency at harvest. Different endophyte strains produced the same results in host plant water relations and stomatal responses. These stomatal responses were also observed under elevated CO2 conditions, and the increase in water use efficiency was more pronounced under water deficit conditions. The effect on water use efficiency was positively correlated with daily light integrals across different experiments. Our results provide insights on the physiological mechanisms of plant-endophyte interactions involving plant water relations and stomatal functions.
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Affiliation(s)
- Hyungmin Rho
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Victor Van Epps
- Department of Biology, University of Washington, Seattle, WA, United States
| | - Nicholas Wegley
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Sharon L. Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
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