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Schlechter RO, Miebach M, Remus-Emsermann MN. Driving factors of epiphytic bacterial communities: A review. J Adv Res 2019; 19:57-65. [PMID: 31341670 PMCID: PMC6630024 DOI: 10.1016/j.jare.2019.03.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/29/2022] Open
Abstract
Bacteria establish complex, compositionally consistent communities on healthy leaves. Ecological processes such as dispersal, diversification, ecological drift, and selection as well as leaf surface physicochemistry and topology impact community assembly. Since the leaf surface is an oligotrophic environment, species interactions such as competition and cooperation may be major contributors to shape community structure. Furthermore, the plant immune system impacts on microbial community composition, as plant cells respond to bacterial molecules and shape their responses according to the mixture of molecules present. Such tunability of the plant immune network likely enables the plant host to differentiate between pathogenic and non-pathogenic colonisers, avoiding costly immune responses to non-pathogenic colonisers. Plant immune responses are either systemically distributed or locally confined, which in turn affects the colonisation pattern of the associated microbiota. However, how each of these factors impacts the bacterial community is unclear. To better understand this impact, bacterial communities need to be studied at a micrometre resolution, which is the scale that is relevant to the members of the community. Here, current insights into the driving factors influencing the assembly of leaf surface-colonising bacterial communities are discussed, with a special focus on plant host immunity as an emerging factor contributing to bacterial leaf colonisation.
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Affiliation(s)
- Rudolf O. Schlechter
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Moritz Miebach
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Mitja N.P. Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
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102
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Luo D, Langendries S, Mendez SG, De Ryck J, Liu D, Beirinckx S, Willems A, Russinova E, Debode J, Goormachtig S. Plant Growth Promotion Driven by a Novel Caulobacter Strain. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1162-1174. [PMID: 30933667 DOI: 10.1094/mpmi-12-18-0347-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Soil microbial communities hold great potential for sustainable and ecologically compatible agriculture. Although numerous plant-beneficial bacterial strains from a wide range of taxonomic groups have been reported, very little evidence is available on the plant-beneficial role of bacteria from the genus Caulobacter. Here, the mode of action of a Caulobacter strain, designated RHG1, which had originally been identified through a microbial screen for plant growth-promoting (PGP) bacteria in maize (Zea mays), is investigated in Arabidopsis thaliana. RHG1 colonized both roots and shoots of Arabidopsis, promoted lateral root formation in the root, and increased leaf number and leaf size in the shoot. The genome of RHG1 was sequenced and was utilized to look for PGP factors. Our data revealed that the bacterial production of nitric oxide, auxins, cytokinins, or 1-aminocyclopropane-1-carboxylate deaminase as PGP factors could be excluded. However, the analysis of brassinosteroid mutants suggests that an unknown PGP mechanism is involved that impinges directly or indirectly on the pathway of this growth hormone.
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Affiliation(s)
- Dexian Luo
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Sarah Langendries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Sonia Garcia Mendez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Joren De Ryck
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Derui Liu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Stien Beirinckx
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Anne Willems
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Jane Debode
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
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103
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Timmermann T, Poupin MJ, Vega A, Urrutia C, Ruz GA, González B. Gene networks underlying the early regulation of Paraburkholderia phytofirmans PsJN induced systemic resistance in Arabidopsis. PLoS One 2019; 14:e0221358. [PMID: 31437216 PMCID: PMC6705864 DOI: 10.1371/journal.pone.0221358] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/05/2019] [Indexed: 01/07/2023] Open
Abstract
Plant defense responses to biotic stresses are complex biological processes, all governed by sophisticated molecular regulations. Induced systemic resistance (ISR) is one of these defense mechanisms where beneficial bacteria or fungi prime plants to resist pathogens or pest attacks. In ISR, the defense arsenal in plants remains dormant and it is only triggered by an infection, allowing a better allocation of plant resources. Our group recently described that the well-known beneficial bacterium Paraburkholderia phytofirmans PsJN is able to induce Arabidopsis thaliana resistance to Pseudomonas syringae pv. tomato (Pst) DC3000 through ISR, and that ethylene, jasmonate and salicylic acid are involved in this protection. Nevertheless, the molecular networks governing this beneficial interaction remain unknown. To tackle this issue, we analyzed the temporal changes in the transcriptome of PsJN-inoculated plants before and after being infected with Pst DC3000. These data were used to perform a gene network analysis to identify highly connected transcription factors. Before the pathogen challenge, the strain PsJN regulated 405 genes (corresponding to 1.8% of the analyzed genome). PsJN-inoculated plants presented a faster and stronger transcriptional response at 1-hour post infection (hpi) compared with the non-inoculated plants, which presented the highest transcriptional changes at 24 hpi. A principal component analysis showed that PsJN-induced plant responses to the pathogen could be differentiated from those induced by the pathogen itself. Forty-eight transcription factors were regulated by PsJN at 1 hpi, and a system biology analysis revealed a network with four clusters. Within these clusters LHY, WRKY28, MYB31 and RRTF1 are highly connected transcription factors, which could act as hub regulators in this interaction. Concordantly with our previous results, these clusters are related to jasmonate, ethylene, salicylic, acid and ROS pathways. These results indicate that a rapid and specific response of PsJN-inoculated plants to the virulent DC3000 strain could be the pivotal element in the protection mechanism.
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Affiliation(s)
- Tania Timmermann
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - María Josefina Poupin
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Andrea Vega
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Cristóbal Urrutia
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Gonzalo A. Ruz
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Bernardo González
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
- * E-mail:
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104
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Nobori T, Tsuda K. The plant immune system in heterogeneous environments. CURRENT OPINION IN PLANT BIOLOGY 2019; 50:58-66. [PMID: 30978554 DOI: 10.1016/j.pbi.2019.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
The plant immune system inhibits pathogen growth and contributes to shaping a healthy microbial community in the plant body. Plants must appropriately respond to both microbial signals and abiotic factors that are diverse in time and space, and thus, proper integration of these inputs at local and systemic levels is of crucial importance for optimal plant responses and fitness in nature. Here, we review our current knowledge of three properties of the plant immune system, resilience, tunability, and balance, which enable plants to deal with complex cocktails of environmental factors. We also discuss future challenges on the path towards a comprehensive understanding of the interactions between plant immunity and pathogenic, non-pathogenic, and beneficial microbes.
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Affiliation(s)
- Tatsuya Nobori
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, Cologne 50829, Germany
| | - Kenichi Tsuda
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, Cologne 50829, Germany.
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105
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Stringlis IA, Zhang H, Pieterse CMJ, Bolton MD, de Jonge R. Microbial small molecules - weapons of plant subversion. Nat Prod Rep 2019; 35:410-433. [PMID: 29756135 DOI: 10.1039/c7np00062f] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Covering: up to 2018 Plants live in close association with a myriad of microbes that are generally harmless. However, the minority of microbes that are pathogens can severely impact crop quality and yield, thereby endangering food security. By contrast, beneficial microbes provide plants with important services, such as enhanced nutrient uptake and protection against pests and diseases. Like pathogens, beneficial microbes can modulate host immunity to efficiently colonize the nutrient-rich niches within and around the roots and aerial tissues of a plant, a phenomenon mirroring the establishment of commensal microbes in the human gut. Numerous ingenious mechanisms have been described by which pathogenic and beneficial microbes in the plant microbiome communicate with their host, including the delivery of immune-suppressive effector proteins and the production of phytohormones, toxins and other bioactive molecules. Plants signal to their associated microbes via exudation of photosynthetically fixed carbon sources, quorum-sensing mimicry molecules and selective secondary metabolites such as strigolactones and flavonoids. Molecular communication thus forms an integral part of the establishment of both beneficial and pathogenic plant-microbe relations. Here, we review the current knowledge on microbe-derived small molecules that can act as signalling compounds to stimulate plant growth and health by beneficial microbes on the one hand, but also as weapons for plant invasion by pathogens on the other. As an exemplary case, we used comparative genomics to assess the small molecule biosynthetic capabilities of the Pseudomonas genus; a genus rich in both plant pathogenic and beneficial microbes. We highlight the biosynthetic potential of individual microbial genomes and the population at large, providing evidence for the hypothesis that the distinction between detrimental and beneficial microbes is increasingly fading. Knowledge on the biosynthesis and molecular activity of microbial small molecules will aid in the development of successful biological agents boosting crop resiliency in a sustainable manner and could also provide scientific routes to pathogen inhibition or eradication.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, The Netherlands.
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106
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Stringlis IA, Zamioudis C, Berendsen RL, Bakker PAHM, Pieterse CMJ. Type III Secretion System of Beneficial Rhizobacteria Pseudomonas simiae WCS417 and Pseudomonas defensor WCS374. Front Microbiol 2019; 10:1631. [PMID: 31379783 PMCID: PMC6647874 DOI: 10.3389/fmicb.2019.01631] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/02/2019] [Indexed: 11/13/2022] Open
Abstract
Plants roots host myriads of microbes, some of which enhance the defense potential of plants by activating a broad-spectrum immune response in leaves, known as induced systemic resistance (ISR). Nevertheless, establishment of this mutualistic interaction requires active suppression of local root immune responses to allow successful colonization. To facilitate host colonization, phytopathogenic bacteria secrete immune-suppressive effectors into host cells via the type III secretion system (T3SS). Previously, we searched the genomes of the ISR-inducing rhizobacteria Pseudomonas simiae WCS417 and Pseudomonas defensor WCS374 for the presence of a T3SS and identified the components for a T3SS in the genomes of WCS417 and WCS374. By performing a phylogenetic and gene cluster alignment analysis we show that the T3SS of WCS417 and WCS374 are grouped in a clade that is enriched for beneficial rhizobacteria. We also found sequences of putative novel effectors in their genomes, which may facilitate future research on the role of T3SS effectors in plant-beneficial microbe interactions in the rhizosphere.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Christos Zamioudis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Roeland L Berendsen
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Peter A H M Bakker
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Corné M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
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107
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Stringlis IA, de Jonge R, Pieterse CMJ. The Age of Coumarins in Plant-Microbe Interactions. PLANT & CELL PHYSIOLOGY 2019; 60:1405-1419. [PMID: 31076771 PMCID: PMC6915228 DOI: 10.1093/pcp/pcz076] [Citation(s) in RCA: 144] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 04/23/2019] [Indexed: 05/05/2023]
Abstract
Coumarins are a family of plant-derived secondary metabolites that are produced via the phenylpropanoid pathway. In the past decade, coumarins have emerged as iron-mobilizing compounds that are secreted by plant roots and aid in iron uptake from iron-deprived soils. Members of the coumarin family are found in many plant species. Besides their role in iron uptake, coumarins have been extensively studied for their potential to fight infections in both plants and animals. Coumarin activities range from antimicrobial and antiviral to anticoagulant and anticancer. In recent years, studies in the model plant species tobacco and Arabidopsis have significantly increased our understanding of coumarin biosynthesis, accumulation, secretion, chemical modification and their modes of action against plant pathogens. Here, we review current knowledge on coumarins in different plant species. We focus on simple coumarins and provide an overview on their biosynthesis and role in environmental stress responses, with special attention for the recently discovered semiochemical role of coumarins in aboveground and belowground plant-microbe interactions and the assembly of the root microbiome.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
- Corresponding author: E-mail, ; Fax,+31 30 253 2837
| | - Ronnie de Jonge
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Corn� M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
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108
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Fernández I, Cosme M, Stringlis IA, Yu K, de Jonge R, van Wees SM, Pozo MJ, Pieterse CMJ, van der Heijden MGA. Molecular dialogue between arbuscular mycorrhizal fungi and the nonhost plant Arabidopsis thaliana switches from initial detection to antagonism. THE NEW PHYTOLOGIST 2019; 223:867-881. [PMID: 30883790 DOI: 10.1111/nph.15798] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
Approximately 29% of all vascular plant species are unable to establish an arbuscular mycorrhizal (AM) symbiosis. Despite this, AM fungi (Rhizophagus spp.) are enriched in the root microbiome of the nonhost Arabidopsis thaliana, and Arabidopsis roots become colonized when AM networks nurtured by host plants are available. Here, we investigated the nonhost-AM fungus interaction by analyzing transcriptional changes in Rhizophagus, Arabidopsis and the host plant Medicago truncatula while growing in the same mycorrhizal network. In early interaction stages, Rhizophagus activated the Arabidopsis strigolactone biosynthesis genes CCD7 and CCD8, suggesting that detection of AM fungi is not completely impaired. However, in colonized Arabidopsis roots, fungal nutrient transporter genes GintPT, GintAMT2, GintMST2 and GintMST4, essential for AM symbiosis, were not activated. RNA-seq transcriptome analysis pointed to activation of costly defenses in colonized Arabidopsis roots. Moreover, Rhizophagus colonization caused a 50% reduction in shoot biomass, but also led to enhanced systemic immunity against Botrytis cinerea. This suggests that early signaling between AM fungi and Arabidopsis is not completely impaired and that incompatibility appears at later interaction stages. Moreover, Rhizophagus-mediated defenses coincide with reduced Arabidopsis growth, but also with systemic disease resistance, highlighting the multifunctional role of AM fungi in host and nonhost interactions.
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Affiliation(s)
- Iván Fernández
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Marco Cosme
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Ke Yu
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Ronnie de Jonge
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, B-9052, Belgium
| | - SaskiaC M van Wees
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Maria J Pozo
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (CSIC), Granada, 18008, Spain
| | - Corné M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
| | - Marcel G A van der Heijden
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB, Utrecht, the Netherlands
- Plant-Soil-Interactions, Agroscope, Zürich, 8046, Switzerland
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109
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Xu L, Coleman-Derr D. Causes and consequences of a conserved bacterial root microbiome response to drought stress. Curr Opin Microbiol 2019; 49:1-6. [DOI: 10.1016/j.mib.2019.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/24/2019] [Accepted: 07/29/2019] [Indexed: 10/26/2022]
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110
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Scotti R, D’Agostino N, Zaccardelli M. Gene expression profiling of tomato roots interacting with Pseudomonas fluorescens unravels the molecular reprogramming that occurs during the early phases of colonization. Symbiosis 2019. [DOI: 10.1007/s13199-019-00611-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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111
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A halotolerant growth promoting rhizobacteria triggers induced systemic resistance in plants and defends against fungal infection. Sci Rep 2019; 9:4054. [PMID: 30858512 PMCID: PMC6411892 DOI: 10.1038/s41598-019-40930-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/26/2019] [Indexed: 12/17/2022] Open
Abstract
A halotolerant rhizobacteria, Klebsiella species (referred to MBE02), was identified that had a growth stimulation effect on peanut. To gain mechanistic insights into how molecular components were reprogrammed during the interaction of MBE02 and peanut roots, we performed deep RNA-sequencing. In total, 1260 genes were differentially expressed: 979 genes were up-regulated, whereas 281 were down-regulated by MBE02 treatment as compared to uninoculated controls. A large component of the differentially regulated genes were related to phytohormone signalling. This included activation of a significant proportion of genes involved in jasmonic acid, ethylene and pathogen-defense signalling, which indicated a role of MBE02 in modulating plant immunity. In vivo and in vitro pathogenesis assays demonstrated that MBE02 treatment indeed provide fitness benefits to peanut against Aspergillus infection under controlled as well as field environment. Further, MBE02 directly reduced the growth of a wide range of fungal pathogens including Aspergillus. We also identified possible molecular components involved in rhizobacteria-mediated plant protection. Our results show the potential of MBE02 as a biocontrol agent in preventing infection against several fungal phytopathogens.
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112
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Romera FJ, García MJ, Lucena C, Martínez-Medina A, Aparicio MA, Ramos J, Alcántara E, Angulo M, Pérez-Vicente R. Induced Systemic Resistance (ISR) and Fe Deficiency Responses in Dicot Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:287. [PMID: 30915094 PMCID: PMC6421314 DOI: 10.3389/fpls.2019.00287] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/21/2019] [Indexed: 05/03/2023]
Abstract
Plants develop responses to abiotic stresses, like Fe deficiency. Similarly, plants also develop responses to cope with biotic stresses provoked by biological agents, like pathogens and insects. Some of these responses are limited to the infested damaged organ, but other responses systemically spread far from the infested organ and affect the whole plant. These latter responses include the Systemic Acquired Resistance (SAR) and the Induced Systemic Resistance (ISR). SAR is induced by pathogens and insects while ISR is mediated by beneficial microbes living in the rhizosphere, like bacteria and fungi. These root-associated mutualistic microbes, besides impacting on plant nutrition and growth, can further boost plant defenses, rendering the entire plant more resistant to pathogens and pests. In the last years, it has been found that ISR-eliciting microbes can induce both physiological and morphological responses to Fe deficiency in dicot plants. These results suggest that the regulation of both ISR and Fe deficiency responses overlap, at least partially. Indeed, several hormones and signaling molecules, like ethylene (ET), auxin, and nitric oxide (NO), and the transcription factor MYB72, emerged as key regulators of both processes. This convergence between ISR and Fe deficiency responses opens the way to the use of ISR-eliciting microbes as Fe biofertilizers as well as biopesticides. This review summarizes the progress in the understanding of the molecular overlap in the regulation of ISR and Fe deficiency responses in dicot plants. Root-associated mutualistic microbes, rhizobacteria and rhizofungi species, known for their ability to induce morphological and/or physiological responses to Fe deficiency in dicot plant species are also reviewed herein.
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Affiliation(s)
- Francisco J. Romera
- Department of Agronomy, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - María J. García
- Department of Botany, Ecology and Plant Physiology, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Carlos Lucena
- Department of Botany, Ecology and Plant Physiology, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Ainhoa Martínez-Medina
- Molecular Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Miguel A. Aparicio
- Department of Microbiology, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - José Ramos
- Department of Microbiology, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Esteban Alcántara
- Department of Agronomy, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Macarena Angulo
- Department of Agronomy, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Rafael Pérez-Vicente
- Department of Botany, Ecology and Plant Physiology, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
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113
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Pfeilmeier S, George J, Morel A, Roy S, Smoker M, Stransfeld L, Downie JA, Peeters N, Malone JG, Zipfel C. Expression of the Arabidopsis thaliana immune receptor EFR in Medicago truncatula reduces infection by a root pathogenic bacterium, but not nitrogen-fixing rhizobial symbiosis. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:569-579. [PMID: 30120864 PMCID: PMC6381793 DOI: 10.1111/pbi.12999] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 07/11/2018] [Accepted: 08/13/2018] [Indexed: 05/12/2023]
Abstract
Interfamily transfer of plant pattern recognition receptors (PRRs) represents a promising biotechnological approach to engineer broad-spectrum, and potentially durable, disease resistance in crops. It is however unclear whether new recognition specificities to given pathogen-associated molecular patterns (PAMPs) affect the interaction of the recipient plant with beneficial microbes. To test this in a direct reductionist approach, we transferred the Brassicaceae-specific PRR ELONGATION FACTOR-THERMO UNSTABLE RECEPTOR (EFR), conferring recognition of the bacterial EF-Tu protein, from Arabidopsis thaliana to the legume Medicago truncatula. Constitutive EFR expression led to EFR accumulation and activation of immune responses upon treatment with the EF-Tu-derived elf18 peptide in leaves and roots. The interaction of M. truncatula with the bacterial symbiont Sinorhizobium meliloti is characterized by the formation of root nodules that fix atmospheric nitrogen. Although nodule numbers were slightly reduced at an early stage of the infection in EFR-Medicago when compared to control lines, nodulation was similar in all lines at later stages. Furthermore, nodule colonization by rhizobia, and nitrogen fixation were not compromised by EFR expression. Importantly, the M. truncatula lines expressing EFR were substantially more resistant to the root bacterial pathogen Ralstonia solanacearum. Our data suggest that the transfer of EFR to M. truncatula does not impede root nodule symbiosis, but has a positive impact on disease resistance against a bacterial pathogen. In addition, our results indicate that Rhizobium can either avoid PAMP recognition during the infection process, or is able to actively suppress immune signaling.
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Affiliation(s)
- Sebastian Pfeilmeier
- The Sainsbury LaboratoryNorwich Research ParkNorwichUK
- John Innes CentreNorwich Research ParkNorwichUK
- Present address:
Institute of MicrobiologyDepartment of BiologyETH ZurichZurich8093Switzerland
| | | | - Arry Morel
- INRALaboratoire des Interactions Plantes Micro‐organismes (LIPM)UMR441Castanet‐TolosanFrance
- CNRSLaboratoire des Interactions Plantes Micro‐organismes (LIPM)UMR2594Castanet‐TolosanFrance
| | - Sonali Roy
- John Innes CentreNorwich Research ParkNorwichUK
- Present address:
Noble Research InstituteArdmoreOKUSA
| | | | - Lena Stransfeld
- The Sainsbury LaboratoryNorwich Research ParkNorwichUK
- Institute of Plant and Microbial Biology & Zurich‐Basel Plant Science CenterUniversity of ZurichZurichSwitzerland
| | | | - Nemo Peeters
- INRALaboratoire des Interactions Plantes Micro‐organismes (LIPM)UMR441Castanet‐TolosanFrance
- CNRSLaboratoire des Interactions Plantes Micro‐organismes (LIPM)UMR2594Castanet‐TolosanFrance
| | - Jacob G. Malone
- John Innes CentreNorwich Research ParkNorwichUK
- School of Biological SciencesUniversity of East AngliaNorwichUK
| | - Cyril Zipfel
- The Sainsbury LaboratoryNorwich Research ParkNorwichUK
- Institute of Plant and Microbial Biology & Zurich‐Basel Plant Science CenterUniversity of ZurichZurichSwitzerland
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114
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Garrido-Oter R, Nakano RT, Dombrowski N, Ma KW, McHardy AC, Schulze-Lefert P. Modular Traits of the Rhizobiales Root Microbiota and Their Evolutionary Relationship with Symbiotic Rhizobia. Cell Host Microbe 2019; 24:155-167.e5. [PMID: 30001518 PMCID: PMC6053594 DOI: 10.1016/j.chom.2018.06.006] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/16/2018] [Accepted: 06/15/2018] [Indexed: 11/19/2022]
Abstract
Rhizobia are a paraphyletic group of soil-borne bacteria that induce nodule organogenesis in legume roots and fix atmospheric nitrogen for plant growth. In non-leguminous plants, species from the Rhizobiales order define a core lineage of the plant microbiota, suggesting additional functional interactions with plant hosts. In this work, genome analyses of 1,314 Rhizobiales isolates along with amplicon studies of the root microbiota reveal the evolutionary history of nitrogen-fixing symbiosis in this bacterial order. Key symbiosis genes were acquired multiple times, and the most recent common ancestor could colonize roots of a broad host range. In addition, root growth promotion is a characteristic trait of Rhizobiales in Arabidopsis thaliana, whereas interference with plant immunity constitutes a separate, strain-specific phenotype of root commensal Alphaproteobacteria. Additional studies with a tripartite gnotobiotic plant system reveal that these traits operate in a modular fashion and thus might be relevant to microbial homeostasis in healthy roots.
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Affiliation(s)
- Ruben Garrido-Oter
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany; Cluster of Excellence on Plant Sciences, Dusseldorf 40225, Germany
| | - Ryohei Thomas Nakano
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany; Cluster of Excellence on Plant Sciences, Dusseldorf 40225, Germany
| | - Nina Dombrowski
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany; University of Texas Austin, Marine Science Institute, Port Aransas, TX 78373, USA
| | - Ka-Wai Ma
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany
| | - Alice C McHardy
- Department of Computational Biology of Infection Research, Helmholtz Center for Infection Research, Braunschweig 38124, Germany
| | - Paul Schulze-Lefert
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany; Cluster of Excellence on Plant Sciences, Dusseldorf 40225, Germany.
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115
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Verbon EH, Trapet PL, Kruijs S, Temple-Boyer-Dury C, Rouwenhorst TG, Pieterse CMJ. Rhizobacteria-Mediated Activation of the Fe Deficiency Response in Arabidopsis Roots: Impact on Fe Status and Signaling. FRONTIERS IN PLANT SCIENCE 2019; 10:909. [PMID: 31354776 PMCID: PMC6639660 DOI: 10.3389/fpls.2019.00909] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/26/2019] [Indexed: 05/16/2023]
Abstract
The beneficial root-colonizing rhizobacterium Pseudomonas simiae WCS417 stimulates plant growth and induces systemic resistance against a broad spectrum of plant diseases. In Arabidopsis thaliana (Arabidopsis), the root transcriptional response to WCS417 shows significant overlap with the root response to iron (Fe) starvation, including activation of the marker genes MYB72 and IRT1. Here, we investigated how colonization of Arabidopsis roots by WCS417 impacts Fe homeostasis in roots and shoots. Under Fe-sufficient conditions, root colonization by WCS417 induced a transient Fe deficiency response in the root and elevated both the total amount of Fe in the shoot and the shoot fresh weight. When plants were grown under Fe-starvation conditions, WCS417 still promoted plant growth, but did not increase the total amount of Fe, resulting in chlorosis. Thus, increased Fe uptake in response to WCS417 is essential to maintain Fe homeostasis in the more rapidly growing plant. As the WCS417-induced Fe deficiency response is known to require a shoot-derived signal, we tested whether the Fe deficiency response is activated in response to an increased Fe demand in the more rapidly growing shoot. Exogenous application of Fe to the leaves to reduce a potential shoot Fe shortage did not prevent WCS417-mediated induction of the Fe deficiency response in the roots. Moreover, the leaf Fe status-dependent shoot-to-root signaling mutant opt3-2, which is impaired in the phloem-specific Fe transporter OPT3, still up-regulated the Fe deficiency response genes MYB72 and IRT1 in response to WCS417. Collectively, our results suggest that the WCS417-induced Fe deficiency response in the root is controlled by a shoot-to-root signaling system that functions independently of both leaf Fe status and OPT3.
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Affiliation(s)
- Eline H. Verbon
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Pauline L. Trapet
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Sophie Kruijs
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Coline Temple-Boyer-Dury
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - T. Gerrit Rouwenhorst
- Ecology and Biodiversity, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Corné M. J. Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
- *Correspondence: Corné M. J. Pieterse,
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116
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Pascale A, Proietti S, Pantelides IS, Stringlis IA. Modulation of the Root Microbiome by Plant Molecules: The Basis for Targeted Disease Suppression and Plant Growth Promotion. FRONTIERS IN PLANT SCIENCE 2019; 10:1741. [PMID: 32038698 PMCID: PMC6992662 DOI: 10.3389/fpls.2019.01741] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/11/2019] [Indexed: 05/18/2023]
Abstract
Plants host a mesmerizing diversity of microbes inside and around their roots, known as the microbiome. The microbiome is composed mostly of fungi, bacteria, oomycetes, and archaea that can be either pathogenic or beneficial for plant health and fitness. To grow healthy, plants need to surveil soil niches around the roots for the detection of pathogenic microbes, and in parallel maximize the services of beneficial microbes in nutrients uptake and growth promotion. Plants employ a palette of mechanisms to modulate their microbiome including structural modifications, the exudation of secondary metabolites and the coordinated action of different defence responses. Here, we review the current understanding on the composition and activity of the root microbiome and how different plant molecules can shape the structure of the root-associated microbial communities. Examples are given on interactions that occur in the rhizosphere between plants and soilborne fungi. We also present some well-established examples of microbiome harnessing to highlight how plants can maximize their fitness by selecting their microbiome. Understanding how plants manipulate their microbiome can aid in the design of next-generation microbial inoculants for targeted disease suppression and enhanced plant growth.
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Affiliation(s)
- Alberto Pascale
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
| | - Silvia Proietti
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Iakovos S. Pantelides
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol, Cyprus
- *Correspondence: Iakovos S. Pantelides, ; Ioannis A. Stringlis,
| | - Ioannis A. Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
- *Correspondence: Iakovos S. Pantelides, ; Ioannis A. Stringlis,
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117
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Cecchini NM, Roychoudhry S, Speed DJ, Steffes K, Tambe A, Zodrow K, Konstantinoff K, Jung HW, Engle NL, Tschaplinski TJ, Greenberg JT. Underground Azelaic Acid-Conferred Resistance to Pseudomonas syringae in Arabidopsis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:86-94. [PMID: 30156481 DOI: 10.1094/mpmi-07-18-0185-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Local interactions between individual plant organs and diverse microorganisms can lead to whole plant immunity via the mobilization of defense signals. One such signal is the plastid lipid-derived oxylipin azelaic acid (AZA). Arabidopsis lacking AZI1 or EARLI1, related lipid transfer family proteins, exhibit reduced AZA transport among leaves and cannot mount systemic immunity. AZA has been detected in roots as well as leaves. Therefore, the present study addresses the effects on plants of AZA application to roots. AZA but not the structurally related suberic acid inhibits root growth when directly in contact with roots. Treatment of roots with AZA also induces resistance to Pseudomonas syringae in aerial tissues. These effects of AZA on root growth and disease resistance depend, at least partially, on AZI1 and EARLI1. AZI1 in roots localizes to plastids, similar to its known location in leaves. Interestingly, kinases previously shown to modify AZI1 in vitro, MPK3 and MPK6, are also needed for AZA-induced root-growth inhibition and aboveground immunity. Finally, deuterium-labeled AZA applied to the roots does not move to aerial tissues. Thus, AZA application to roots triggers systemic immunity through an AZI1/EARLI1/MPK3/MPK6-dependent pathway and AZA effects may involve one or more additional mobile signals.
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Affiliation(s)
- Nicolás M Cecchini
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Suruchi Roychoudhry
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - DeQuantarius J Speed
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Kevin Steffes
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Arjun Tambe
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Kristin Zodrow
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Katerina Konstantinoff
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
| | - Ho Won Jung
- 2 Department of Molecular Genetics, Dong-A University, 37 Nakdong-Daero 550beon-gil, Saha-gu, Busan 49315, Korea; and
| | - Nancy L Engle
- 3 Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831, U.S.A
| | | | - Jean T Greenberg
- 1 Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street GCIS 524W, Chicago, IL 60637, U.S.A
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118
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A Genome-Wide Screen Identifies Genes in Rhizosphere-Associated Pseudomonas Required to Evade Plant Defenses. mBio 2018; 9:mBio.00433-18. [PMID: 30401768 PMCID: PMC6222131 DOI: 10.1128/mbio.00433-18] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
While rhizosphere bacteria hold the potential to improve plant health and fitness, little is known about the bacterial genes required to evade host immunity. Using a model system consisting of Arabidopsis and a beneficial Pseudomonas sp. isolate, we identified bacterial genes required for both rhizosphere fitness and for evading host immune responses. This work advances our understanding of how evasion of host defenses contributes to survival in the rhizosphere. Pseudomonas fluorescens and related plant root (“rhizosphere”)-associated species contribute to plant health by modulating defenses and facilitating nutrient uptake. To identify bacterial fitness determinants in the rhizosphere of the model plant Arabidopsis thaliana, we performed a high-throughput transposon sequencing (Tn-Seq) screen using the biocontrol and growth-promoting strain Pseudomonas sp. WCS365. The screen, which was performed in parallel on wild-type and immunocompromised Arabidopsis plants, identified 231 genes that increased fitness in the rhizosphere of wild-type plants. A subset of these genes decreased fitness in the rhizosphere of immunocompromised plants. We hypothesized that these genes might be involved in avoiding plant defenses and verified 7 Pseudomonas sp. WCS365 candidate genes by generating clean deletions. We found that two of these deletion mutants, ΔmorA (encoding a putative diguanylate cyclase/phosphodiesterase) and ΔspuC (encoding a putrescine aminotransferase), formed enhanced biofilms and inhibited plant growth. We found that mutants ΔspuC and ΔmorA induced pattern-triggered immunity (PTI) as measured by induction of an Arabidopsis PTI reporter and FLS2/BAK1-dependent inhibition of plant growth. We show that MorA acts as a phosphodiesterase to inhibit biofilm formation, suggesting a possible role in biofilm dispersal. We found that both putrescine and its precursor arginine promote biofilm formation that is enhanced in the ΔspuC mutant, which cannot break down putrescine, suggesting that putrescine might serve as a signaling molecule in the rhizosphere. Collectively, this work identified novel bacterial factors required to evade plant defenses in the rhizosphere.
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119
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Ikeda-Ohtsubo W, Brugman S, Warden CH, Rebel JMJ, Folkerts G, Pieterse CMJ. How Can We Define "Optimal Microbiota?": A Comparative Review of Structure and Functions of Microbiota of Animals, Fish, and Plants in Agriculture. Front Nutr 2018; 5:90. [PMID: 30333981 PMCID: PMC6176000 DOI: 10.3389/fnut.2018.00090] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/07/2018] [Indexed: 12/21/2022] Open
Abstract
All multicellular organisms benefit from their own microbiota, which play important roles in maintaining the host nutritional health and immunity. Recently, the number of studies on the microbiota of animals, fish, and plants of economic importance is rapidly expanding and there are increasing expectations that productivity and sustainability in agricultural management can be improved by microbiota manipulation. However, optimizing microbiota is still a challenging task because of the lack of knowledge on the dominant microorganisms or significant variations between microbiota, reflecting sampling biases, different agricultural management as well as breeding backgrounds. To offer a more generalized view on microbiota in agriculture, which can be used for defining criteria of “optimal microbiota” as the goal of manipulation, we summarize here current knowledge on microbiota on animals, fish, and plants with emphasis on bacterial community structure and metabolic functions, and how microbiota can be affected by domestication, conventional agricultural practices, and use of antimicrobial agents. Finally, we discuss future tasks for defining “optimal microbiota,” which can improve host growth, nutrition, and immunity and reduce the use of antimicrobial agents in agriculture.
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Affiliation(s)
- Wakako Ikeda-Ohtsubo
- Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Sylvia Brugman
- Cell Biology and Immunology Group, Wageningen University and Research, Wageningen, Netherlands
| | - Craig H Warden
- Departments of Pediatrics, Neurobiology Physiology and Behavior, University of California, Davis, Davis, CA, United States
| | - Johanna M J Rebel
- Wageningen Livestock Research, Wageningen University and Research, Wageningen, Netherlands
| | - Gert Folkerts
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Corné M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
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120
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Manganiello G, Sacco A, Ercolano MR, Vinale F, Lanzuise S, Pascale A, Napolitano M, Lombardi N, Lorito M, Woo SL. Modulation of Tomato Response to Rhizoctonia solani by Trichoderma harzianum and Its Secondary Metabolite Harzianic Acid. Front Microbiol 2018; 9:1966. [PMID: 30233507 PMCID: PMC6127634 DOI: 10.3389/fmicb.2018.01966] [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: 04/26/2018] [Accepted: 08/02/2018] [Indexed: 01/25/2023] Open
Abstract
The present study investigated the transcriptomic and metabolomic changes elicited in tomato plants (Solanum lycopersicum cv. Micro-Tom) following treatments with the biocontrol agent Trichoderma harzianum strain M10 or its purified secondary metabolite harzianic acid (HA), in the presence or the absence of the soil-borne pathogen Rhizoctonia solani. Transcriptomic analysis allowed the identification of differentially expressed genes (DEGs) that play a pivotal role in resistance to biotic stress. Overall, the results support the ability of T. harzianum M10 to activate defense responses in infected tomato plants. An induction of hormone-mediated signaling was observed, as shown by the up-regulation of genes involved in the ethylene and jasmonate (ET/JA) and salicylic acid (SA)-mediated signaling pathways. Further, the protective action of T. harzianum on the host was revealed by the over-expression of genes able to detoxify cells from reactive oxygen species (ROS). On the other hand, HA treatment also stimulated tomato response to the pathogen by inducing the expression of several genes involved in defense response (including protease inhibitors, resistance proteins like CC-NBS-LRR) and hormone interplay. The accumulation of steroidal glycoalkaloids in the plant after treatments with either T. harzianum or HA, as determined by metabolomic analysis, confirmed the complexity of the plant response to beneficial microbes, demonstrating that these microorganisms are also capable of activating the chemical defenses.
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Affiliation(s)
- Gelsomina Manganiello
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Adriana Sacco
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Maria R. Ercolano
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Francesco Vinale
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
| | - Stefania Lanzuise
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Alberto Pascale
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Mauro Napolitano
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
| | - Nadia Lombardi
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
| | - Matteo Lorito
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
| | - Sheridan L. Woo
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
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121
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Sharifi R, Ryu CM. Sniffing bacterial volatile compounds for healthier plants. CURRENT OPINION IN PLANT BIOLOGY 2018; 44:88-97. [PMID: 29579577 DOI: 10.1016/j.pbi.2018.03.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 05/19/2023]
Abstract
Bacterial volatile compounds (BVCs) are not waste or by-products of primary metabolism but rather have critical roles in the biology and ecological competence of bacteria. BVCs are exploited as a source of nutrients and information in plant-bacteria interactions. They target key points in plant physiology, activating downstream metabolic pathways by a domino effect. BVCs are an ancient signal and are involved in plant-bacteria communication, which was shaped during evolutionary history and established before the development of higher plants. This type of communication is not exclusive to mutualistic interactions, because pathogens also use volatiles to alter plant physiology. Here, fragmented information is drawn together to provide a clearer view of how BVCs affect such interactions.
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Affiliation(s)
- Rouhallah Sharifi
- Department of Plant Protection, College of Agriculture and Natural Resources, Razi University, Kermanshah, Iran
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, Infectious Disease Research Center, KRIBB, Daejeon 34141, South Korea; Biosystem and Bioengineering Program, University of Science and Technology (UST), Daejeon 34141, South Korea.
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122
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Xu L, Wu C, Oelmüller R, Zhang W. Role of Phytohormones in Piriformospora indica-Induced Growth Promotion and Stress Tolerance in Plants: More Questions Than Answers. Front Microbiol 2018; 9:1646. [PMID: 30140257 PMCID: PMC6094092 DOI: 10.3389/fmicb.2018.01646] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 07/02/2018] [Indexed: 11/18/2022] Open
Abstract
Phytohormones play vital roles in the growth and development of plants as well as in interactions of plants with microbes such as endophytic fungi. The endophytic root-colonizing fungus Piriformospora indica promotes plant growth and performance, increases resistance of colonized plants to pathogens, insects and abiotic stress. Here, we discuss the roles of the phytohormones (auxins, cytokinin, gibberellins, abscisic acid, ethylene, salicylic acid, jasmonates, and brassinosteroids) in the interaction of P. indica with higher plant species, and compare available data with those from other (beneficial) microorganisms interacting with roots. Crosstalks between different hormones in balancing the plant responses to microbial signals is an emerging topic in current research. Furthermore, phytohormones play crucial roles in systemic signal propagation as well as interplant communication. P. indica interferes with plant hormone synthesis and signaling to stimulate growth, flowering time, differentiation and local and systemic immune responses. Plants adjust their hormone levels in the roots in response to the microbes to control colonization and fungal propagation. The available information on the roles of phytohormones in beneficial root-microbe interactions opens new questions of how P. indica manipulates the plant hormone metabolism to promote the benefits for both partners in the symbiosis.
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Affiliation(s)
- Le Xu
- Hubei Collaborative Innovation Center for Grain Industry, School of Agriculture, Yangtze University, Jingzhou, China
| | - Chu Wu
- College of Horticulture and Gardening, Yangtze University, Jingzhou, China
| | - Ralf Oelmüller
- Matthias-Schleiden-Institute, Plant Physiology, Friedrich-Schiller-University Jena, Jena, Germany
| | - Wenying Zhang
- Hubei Collaborative Innovation Center for Grain Industry, School of Agriculture, Yangtze University, Jingzhou, China
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123
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Stringlis IA, Yu K, Feussner K, de Jonge R, Van Bentum S, Van Verk MC, Berendsen RL, Bakker PAHM, Feussner I, Pieterse CMJ. MYB72-dependent coumarin exudation shapes root microbiome assembly to promote plant health. Proc Natl Acad Sci U S A 2018; 115:E5213-E5222. [PMID: 29686086 DOI: 10.1094/pbiomes-11-18-0050-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Plant roots nurture a tremendous diversity of microbes via exudation of photosynthetically fixed carbon sources. In turn, probiotic members of the root microbiome promote plant growth and protect the host plant against pathogens and pests. In the Arabidopsis thaliana-Pseudomonas simiae WCS417 model system the root-specific transcription factor MYB72 and the MYB72-controlled β-glucosidase BGLU42 emerged as important regulators of beneficial rhizobacteria-induced systemic resistance (ISR) and iron-uptake responses. MYB72 regulates the biosynthesis of iron-mobilizing fluorescent phenolic compounds, after which BGLU42 activity is required for their excretion into the rhizosphere. Metabolite fingerprinting revealed the antimicrobial coumarin scopoletin as a dominant metabolite that is produced in the roots and excreted into the rhizosphere in a MYB72- and BGLU42-dependent manner. Shotgun-metagenome sequencing of root-associated microbiota of Col-0, myb72, and the scopoletin biosynthesis mutant f6'h1 showed that scopoletin selectively impacts the assembly of the microbial community in the rhizosphere. We show that scopoletin selectively inhibits the soil-borne fungal pathogens Fusarium oxysporum and Verticillium dahliae, while the growth-promoting and ISR-inducing rhizobacteria P. simiae WCS417 and Pseudomonas capeferrum WCS358 are highly tolerant of the antimicrobial effect of scopoletin. Collectively, our results demonstrate a role for coumarins in microbiome assembly and point to a scenario in which plants and probiotic rhizobacteria join forces to trigger MYB72/BGLU42-dependent scopolin production and scopoletin excretion, resulting in improved niche establishment for the microbial partner and growth and immunity benefits for the host plant.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Ke Yu
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Kirstin Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
| | - Ronnie de Jonge
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
- Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Sietske Van Bentum
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Marcel C Van Verk
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Roeland L Berendsen
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Peter A H M Bakker
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
- Department of Plant Biochemistry, Göttingen Center for Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Corné M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, 3508 TB Utrecht, The Netherlands;
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MYB72-dependent coumarin exudation shapes root microbiome assembly to promote plant health. Proc Natl Acad Sci U S A 2018; 115:E5213-E5222. [PMID: 29686086 PMCID: PMC5984513 DOI: 10.1073/pnas.1722335115] [Citation(s) in RCA: 428] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Plant roots nurture a large diversity of soil microbes via exudation of chemical compounds into the rhizosphere. In turn, beneficial root microbiota promote plant growth and immunity. The root-specific transcription factor MYB72 has emerged as a central regulator in this process. Here, we show that MYB72 regulates the excretion of the coumarin scopoletin, an iron-mobilizing phenolic compound with selective antimicrobial activity that shapes the root-associated microbial community. Selected soil-borne fungal pathogens appeared to be highly sensitive to the antimicrobial activity of scopoletin, while two MYB72-inducing beneficial rhizobacteria were tolerant. Our results suggest that probiotic root-associated microbes that activate the iron-deficiency response during colonization stimulate MYB72-dependent excretion of scopoletin, thereby potentially improving their niche establishment and enhancing plant growth and protection. Plant roots nurture a tremendous diversity of microbes via exudation of photosynthetically fixed carbon sources. In turn, probiotic members of the root microbiome promote plant growth and protect the host plant against pathogens and pests. In the Arabidopsis thaliana–Pseudomonas simiae WCS417 model system the root-specific transcription factor MYB72 and the MYB72-controlled β-glucosidase BGLU42 emerged as important regulators of beneficial rhizobacteria-induced systemic resistance (ISR) and iron-uptake responses. MYB72 regulates the biosynthesis of iron-mobilizing fluorescent phenolic compounds, after which BGLU42 activity is required for their excretion into the rhizosphere. Metabolite fingerprinting revealed the antimicrobial coumarin scopoletin as a dominant metabolite that is produced in the roots and excreted into the rhizosphere in a MYB72- and BGLU42-dependent manner. Shotgun-metagenome sequencing of root-associated microbiota of Col-0, myb72, and the scopoletin biosynthesis mutant f6′h1 showed that scopoletin selectively impacts the assembly of the microbial community in the rhizosphere. We show that scopoletin selectively inhibits the soil-borne fungal pathogens Fusarium oxysporum and Verticillium dahliae, while the growth-promoting and ISR-inducing rhizobacteria P. simiae WCS417 and Pseudomonas capeferrum WCS358 are highly tolerant of the antimicrobial effect of scopoletin. Collectively, our results demonstrate a role for coumarins in microbiome assembly and point to a scenario in which plants and probiotic rhizobacteria join forces to trigger MYB72/BGLU42-dependent scopolin production and scopoletin excretion, resulting in improved niche establishment for the microbial partner and growth and immunity benefits for the host plant.
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