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Zwyssig M, Spescha A, Patt T, Belosevic A, Machado RAR, Regaiolo A, Keel C, Maurhofer M. Entomopathogenic pseudomonads can share an insect host with entomopathogenic nematodes and their mutualistic bacteria. THE ISME JOURNAL 2024; 18:wrae028. [PMID: 38381653 PMCID: PMC10945363 DOI: 10.1093/ismejo/wrae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/01/2024] [Accepted: 02/15/2024] [Indexed: 02/23/2024]
Abstract
A promising strategy to overcome limitations in biological control of insect pests is the combined application of entomopathogenic pseudomonads (EPPs) and nematodes (EPNs) associated with mutualistic bacteria (NABs). Yet, little is known about interspecies interactions such as competition, coexistence, or even cooperation between these entomopathogens when they infect the same insect host. We investigated the dynamics of bacteria-bacteria interactions between the EPP Pseudomonas protegens CHA0 and the NAB Xenorhabdus bovienii SM5 isolated from the EPN Steinernema feltiae RS5. Bacterial populations were assessed over time in experimental systems of increasing complexity. In vitro, SM5 was outcompeted when CHA0 reached a certain cell density, resulting in the collapse of the SM5 population. In contrast, both bacteria were able to coexist upon haemolymph-injection into Galleria mellonella larvae, as found for three further EPP-NAB combinations. Finally, both bacteria were administered by natural infection routes i.e. orally for CHA0 and nematode-vectored for SM5 resulting in the addition of RS5 to the system. This did not alter bacterial coexistence nor did the presence of the EPP affect nematode reproductive success or progeny virulence. CHA0 benefited from RS5, probably by exploiting access routes formed by the nematodes penetrating the larval gut epithelium. Our results indicate that EPPs are able to share an insect host with EPNs and their mutualistic bacteria without major negative effects on the reproduction of any of the three entomopathogens or the fitness of the nematodes. This suggests that their combination is a promising strategy for biological insect pest control.
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Affiliation(s)
- Maria Zwyssig
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zurich, Switzerland
| | - Anna Spescha
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zurich, Switzerland
| | - Tabea Patt
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zurich, Switzerland
| | - Adrian Belosevic
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zurich, Switzerland
| | - Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology, University of Neuchatel, CH-2000 Neuchatel, Switzerland
| | - Alice Regaiolo
- Johannes-Gutenberg-University Mainz, Institute of Molecular Physiology, Microbiology and Biotechnology, 55128 Mainz, Germany
| | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Monika Maurhofer
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zurich, Switzerland
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Burz SD, Causevic S, Dal Co A, Dmitrijeva M, Engel P, Garrido-Sanz D, Greub G, Hapfelmeier S, Hardt WD, Hatzimanikatis V, Heiman CM, Herzog MKM, Hockenberry A, Keel C, Keppler A, Lee SJ, Luneau J, Malfertheiner L, Mitri S, Ngyuen B, Oftadeh O, Pacheco AR, Peaudecerf F, Resch G, Ruscheweyh HJ, Sahin A, Sanders IR, Slack E, Sunagawa S, Tackmann J, Tecon R, Ugolini GS, Vacheron J, van der Meer JR, Vayena E, Vonaesch P, Vorholt JA. From microbiome composition to functional engineering, one step at a time. Microbiol Mol Biol Rev 2023; 87:e0006323. [PMID: 37947420 PMCID: PMC10732080 DOI: 10.1128/mmbr.00063-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023] Open
Abstract
SUMMARYCommunities of microorganisms (microbiota) are present in all habitats on Earth and are relevant for agriculture, health, and climate. Deciphering the mechanisms that determine microbiota dynamics and functioning within the context of their respective environments or hosts (the microbiomes) is crucially important. However, the sheer taxonomic, metabolic, functional, and spatial complexity of most microbiomes poses substantial challenges to advancing our knowledge of these mechanisms. While nucleic acid sequencing technologies can chart microbiota composition with high precision, we mostly lack information about the functional roles and interactions of each strain present in a given microbiome. This limits our ability to predict microbiome function in natural habitats and, in the case of dysfunction or dysbiosis, to redirect microbiomes onto stable paths. Here, we will discuss a systematic approach (dubbed the N+1/N-1 concept) to enable step-by-step dissection of microbiome assembly and functioning, as well as intervention procedures to introduce or eliminate one particular microbial strain at a time. The N+1/N-1 concept is informed by natural invasion events and selects culturable, genetically accessible microbes with well-annotated genomes to chart their proliferation or decline within defined synthetic and/or complex natural microbiota. This approach enables harnessing classical microbiological and diversity approaches, as well as omics tools and mathematical modeling to decipher the mechanisms underlying N+1/N-1 microbiota outcomes. Application of this concept further provides stepping stones and benchmarks for microbiome structure and function analyses and more complex microbiome intervention strategies.
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Affiliation(s)
- Sebastian Dan Burz
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Senka Causevic
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Alma Dal Co
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
| | - Marija Dmitrijeva
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Philipp Engel
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Daniel Garrido-Sanz
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Gilbert Greub
- Institut de microbiologie, CHUV University Hospital Lausanne, Lausanne, Switzerland
| | | | | | | | - Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | | | | | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | | | - Soon-Jae Lee
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Julien Luneau
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
| | - Lukas Malfertheiner
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Sara Mitri
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Bidong Ngyuen
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Omid Oftadeh
- Laboratory of Computational Systems Biotechnology, EPF Lausanne, Lausanne, Switzerland
| | | | | | - Grégory Resch
- Center for Research and Innovation in Clinical Pharmaceutical Sciences, CHUV University Hospital Lausanne, Lausanne, Switzerland
| | | | - Asli Sahin
- Laboratory of Computational Systems Biotechnology, EPF Lausanne, Lausanne, Switzerland
| | - Ian R. Sanders
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Emma Slack
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | | | - Janko Tackmann
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Robin Tecon
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | | | - Jordan Vacheron
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | | | - Evangelia Vayena
- Laboratory of Computational Systems Biotechnology, EPF Lausanne, Lausanne, Switzerland
| | - Pascale Vonaesch
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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Dlamini SP, Akanmu AO, Babalola OO. Rhizospheric microorganisms: The gateway to a sustainable plant health. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.925802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Plant health is essential for food security, and constitutes a major predictor to safe and sustainable food systems. Over 40% of the global crops' productions are lost to pests, insects, diseases, and weeds, while the routinely used chemical-based pesticides to manage the menace also have detrimental effects on the microbial communities and ecosystem functioning. The rhizosphere serves as the microbial seed bank where microorganisms transform organic and inorganic substances in the rhizosphere into accessible plant nutrients as plants harbor diverse microorganisms such as fungi, bacteria, nematodes, viruses, and protists among others. Although, the pathogenic microbes initiate diseases by infiltrating the protective microbial barrier and plants' natural defense systems in the rhizosphere. Whereas, the process is often circumvented by the beneficial microorganisms which antagonize the pathogens to instill disease resistance. The management of plant health through approaches focused on disease prevention is instrumental to attaining sustainable food security, and safety. Therefore, an in-depth understanding of the evolving and succession of root microbiomes in response to crop development as discussed in this review opens up new-fangled possibilities for reaping the profit of beneficial root–microbiomes' interactions toward attaining sustainable plant health.
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Pronk LJU, Bakker PAHM, Keel C, Maurhofer M, Flury P. The secret life of plant-beneficial rhizosphere bacteria: insects as alternative hosts. Environ Microbiol 2022; 24:3273-3289. [PMID: 35315557 PMCID: PMC9542179 DOI: 10.1111/1462-2920.15968] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/15/2022]
Abstract
Root-colonizing bacteria have been intensively investigated for their intimate relationship with plants and their manifold plant-beneficial activities. They can inhibit growth and activity of pathogens or induce defence responses. In recent years, evidence has emerged that several plant-beneficial rhizosphere bacteria do not only associate with plants but also with insects. Their relationships with insects range from pathogenic to mutualistic and some rhizobacteria can use insects as vectors for dispersal to new host plants. Thus, the interactions of these bacteria with their environment are even more complex than previously thought and can extend far beyond the rhizosphere. The discovery of this secret life of rhizobacteria represents an exciting new field of research that should link the fields of plant-microbe and insect-microbe interactions. In this review, we provide examples of plant-beneficial rhizosphere bacteria that use insects as alternative hosts, and of potentially rhizosphere-competent insect symbionts. We discuss the bacterial traits that may enable a host-switch between plants and insects and further set the multi-host lifestyle of rhizobacteria into an evolutionary and ecological context. Finally, we identify important open research questions and discuss perspectives on the use of these rhizobacteria in agriculture.
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Affiliation(s)
| | | | - Christoph Keel
- Department of Fundamental MicrobiologyUniversity of LausanneLausanneSwitzerland
| | - Monika Maurhofer
- Plant Pathology, Institute of Integrative BiologyETH ZürichZürichSwitzerland
| | - Pascale Flury
- Crop Protection – Phytopathology, Department of Crop SciencesResearch Institute of Organic Agriculture FiBLFrickSwitzerland
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Chu H, Wang H, Zhang Y, Li Z, Wang C, Dai D, Tang M. Inoculation With Ectomycorrhizal Fungi and Dark Septate Endophytes Contributes to the Resistance of Pinus spp. to Pine Wilt Disease. Front Microbiol 2021; 12:687304. [PMID: 34421845 PMCID: PMC8377431 DOI: 10.3389/fmicb.2021.687304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
Pine wilt disease (PWD) is a deadly disease to pines (Pinus spp.) worldwide. The occurrence of PWD can reduce the relative abundance of root ectomycorrhizal fungi (ECMF) and dark septate endophytes (DSE). However, the effects of exogenous ECMF/DSE inoculation on the rhizosphere microbial community structure of Pinus tabulaeformis infected by pine wood nematode (PWN) is little known. Here, we tested how ECMF/DSE may improve resistance to PWD by quantifying microbial carbon biomass and soil enzymatic activity among different treatments at 6 and 9 months after PWN infection. Denaturing gradient gel electrophoresis (DGGE) was used to study the microbial community structure at 3, 6, and 9 months after PWN infection in the rhizosphere of P. tabulaeformis seedlings inoculated with ECMF/DSE. The results showed that exogenous ECMF/DSE inoculation reduced the disease severity caused by PWN infection. After PWN infection, the rhizosphere microbial carbon of seedlings inoculated with Amanita vaginata, Suillus bovinus, Gaeumannomyces cylindrosporus, and Paraphoma chrysanthemicola was 38.16, 49.67, 42.11, and 96.05% higher than that of the control group, respectively. Inoculation of ECMF/DSE inhibited the decrease of rhizosphere microbial biomass caused by PWN infection. The richness and diversity of P. tabulaeformis rhizosphere fungi at 9 months were reduced by PWN infection but partially recovered by the exogenous fungi (ECMF/DSE) inoculation except for P. chrysanthemicola, which indicates a role of ECMF/DSE in maintaining stability of the microbial community. Inoculation with ECMF/DSE increased the beneficial bacterial (Thauera sp., Mesorhizobium sp., etc.) and fungal groups (Tomentella ellisii, Wilcoxina mikolae, etc.) of in the rhizosphere. In summary, exogenous ECMF/DSE inoculation could increase P. tabulaeformis resistance to PWD probably by improving the rhizosphere microenvironment.
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Affiliation(s)
- Honglong Chu
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China.,College of Biological Resource and Food Engineering, Center for Yunnan Plateau Biological Resources Protection and Utilization, Qujing Normal University, Qujing, China.,College of Forestry, Northwest A&F University, Yangling, China
| | - Haihua Wang
- College of Forestry, Northwest A&F University, Yangling, China.,Department of Food Science and Technology, College of Agriculture and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Yanan Zhang
- College of Biological Resource and Food Engineering, Center for Yunnan Plateau Biological Resources Protection and Utilization, Qujing Normal University, Qujing, China
| | - Zhumei Li
- College of Biological Resource and Food Engineering, Center for Yunnan Plateau Biological Resources Protection and Utilization, Qujing Normal University, Qujing, China
| | - Chunyan Wang
- College of Forestry, Northwest A&F University, Yangling, China
| | - Dongqin Dai
- College of Biological Resource and Food Engineering, Center for Yunnan Plateau Biological Resources Protection and Utilization, Qujing Normal University, Qujing, China
| | - Ming Tang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
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Integrative analysis of the microbiome and metabolome in understanding the causes of sugarcane bitterness. Sci Rep 2021; 11:6024. [PMID: 33727648 PMCID: PMC7966368 DOI: 10.1038/s41598-021-85433-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 02/28/2021] [Indexed: 02/07/2023] Open
Abstract
Plant–microbe interactions can modulate the plant metabolome, but there is no information about how different soil microbiomes could affect the sugarcane metabolome and its quality. Here, we collected soil and stalk samples from bitter sugarcane (BS) and sweet sugarcane (SS) to conduct chemical analysis, microbiome and metabolome analysis. Our data revealed lower species diversity in the BS group than in the SS group, and 18 discriminatory OTUs (relative abundance ≥ 0.01%) were identified. Sugarcane metabolomic analysis indicated the different abundances of 247 metabolites between the two groups in which 22 distinct metabolites involved in two flavonoid biosynthesis pathways were revealed. Integrated analysis between soil microbial taxa, stalk chemical components, and soil properties showed that the flavonoid content in stalks and the nitrogen concentration in soil were highly correlated with the soil microbiome composition. Bacteria at the genus level exhibited greater associations with distinct metabolites, and six genera were independently associated with 90.9% of the sugarcane metabolites that play a major metabolic role in sugarcane. In conclusion, this study provided evidences that the interaction between plant–microbiome can change the plant metabolome.
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7
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Li C, Tang B, Cao S, Bao Y, Sun W, Zhao Y, Liu F. Biocontrol ability and action mechanism of dihydromaltophilin against Colletotrichum fructicola causing anthracnose of pear fruit. PEST MANAGEMENT SCIENCE 2021; 77:1061-1069. [PMID: 33012119 DOI: 10.1002/ps.6122] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/03/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Anthracnose caused by Colletotrichum fructicola is one of the most important diseases in pear fruit, resulting in huge economic losses. Public awareness of protecting the environment and food safety, together with pathogen resistance to many key fungicides have led to an urgent need to develop alternative strategies for controlling fruit diseases. Here, the antifungal activity of a natural product, dihydromaltophilin [heat-stable antifungal factor (HSAF)], against C. fructicola in vitro and in vivo was investigated to determine its efficacy for anthracnose management. RESULTS HSAF exhibited pronounced antifungal activity against in vitro mycelial growth of C. fructicola, with a half-inhibition concentration of 0.43 mg L-1 . Hyphae treated with HSAF showed defects such as hyperbranching, swelling and depolarized growth. Conidia germination in the pathogen was inhibited by HSAF in a dose-dependent manner. In the presence of 4 mg L-1 HSAF, conidia germination was significantly delayed, and germ tube growth was inhibited. HSAF at 8 mg L-1 completely blocked conidia germination in C. fructicola. In addition, HSAF disrupted coordination of cytokinesis with growth and nuclear division, induced reactive oxygen species production in conidia, and damaged the integrity of the conidia cell wall. Moreover, an in vivo test confirmed that 50 mg L-1 HSAF significantly reduced the development of anthracnose decay in pear fruit caused by C. fructicola. CONCLUSION HSAF was highly effective in reducing pear anthracnose caused by C. fructicola and has great potential to become a new type of fruit preservative.
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Affiliation(s)
- Chaohui Li
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Bao Tang
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Shulin Cao
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Bao
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- College of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Weibo Sun
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yancun Zhao
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- College of Plant Pathology, Nanjing Agricultural University, Nanjing, China
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Vacheron J, Heiman CM, Keel C. Live cell dynamics of production, explosive release and killing activity of phage tail-like weapons for Pseudomonas kin exclusion. Commun Biol 2021; 4:87. [PMID: 33469108 PMCID: PMC7815802 DOI: 10.1038/s42003-020-01581-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023] Open
Abstract
Interference competition among bacteria requires a highly specialized, narrow-spectrum weaponry when targeting closely-related competitors while sparing individuals from the same clonal population. Here we investigated mechanisms by which environmentally important Pseudomonas bacteria with plant-beneficial activity perform kin interference competition. We show that killing between phylogenetically closely-related strains involves contractile phage tail-like devices called R-tailocins that puncture target cell membranes. Using live-cell imaging, we evidence that R-tailocins are produced at the cell center, transported to the cell poles and ejected by explosive cell lysis. This enables their dispersal over several tens of micrometers to reach targeted cells. We visualize R-tailocin-mediated competition dynamics between closely-related Pseudomonas strains at the single-cell level, both in non-induced condition and upon artificial induction. We document the fatal impact of cellular self-sacrifice coupled to deployment of phage tail-like weaponry in the microenvironment of kin bacterial competitors, emphasizing the necessity for microscale assessment of microbial competitions.
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Affiliation(s)
- Jordan Vacheron
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland
| | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
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Ueda A, Ogasawara S, Horiuchi K. Identification of the genes controlling biofilm formation in the plant commensal Pseudomonas protegens Pf-5. Arch Microbiol 2020; 202:2453-2459. [PMID: 32607723 DOI: 10.1007/s00203-020-01966-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/20/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022]
Abstract
Determinant genes controlling biofilm formation in a plant commensal bacterium, Pseudomonas protegens Pf-5, were identified by transposon mutagenesis. Comprehensive screening of 7500 transposon-inserted mutants led to the isolation of four mutants exhibiting decreased and five mutants exhibiting increased biofilm formation. Mutations in the genes encoding MFS drug resistance transporter, LapA adhesive protein, RetS sensor histidine kinase/response regulator, and HecA adhesin/hemagglutinin led to decreased biofilm formation, indicating that these genes are necessary for biofilm formation in Pf-5. The mutants exhibiting increased biofilm formation had transposon insertions in the genes coding for an outer membrane protein, a GGDEF domain-containing protein, AraC transcriptional regulator, non-ribosomal peptide synthetase OfaB, and the intergenic region of a DNA-binding protein and the Aer aerotaxis receptor, suggesting that these genes are negative regulators of biofilm formation. Some of these mutants also showed altered swimming and swarming motilities, and a negative correlation between biofilm formation and swarming motility was observed. Thus, sessile-motile lifestyle is regulated by divergent regulatory genes in Pf-5.
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Affiliation(s)
- Akihiro Ueda
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan.
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan.
| | - Shinta Ogasawara
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
| | - Keishi Horiuchi
- School of Applied Biological Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
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Fungal-Associated Molecules Induce Key Genes Involved in the Biosynthesis of the Antifungal Secondary Metabolites Nunamycin and Nunapeptin in the Biocontrol Strain Pseudomonas fluorescens In5. Appl Environ Microbiol 2020; 86:AEM.01284-20. [PMID: 32826219 DOI: 10.1128/aem.01284-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/12/2020] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas fluorescens In5 synthesizes the antifungal cyclic lipopeptides (CLPs) nunamycin and nunapeptin, which are similar in structure and genetic organization to the pseudomonas-derived phytotoxins syringomycin and syringopeptin. Regulation of syringomycin and syringopeptin is dependent on the two-component global regulatory system GacS-GacA and the SalA, SyrF, and SyrG transcription factors, which activate syringomycin synthesis in response to plant signal molecules. Previously, we demonstrated that a specific transcription factor, NunF, positively regulates the synthesis of nunamycin and nunapeptin in P. fluorescens In5 and that the nunF gene is upregulated by fungal-associated molecules. This study focused on further unravelling the complex regulation governing CLP synthesis in P. fluorescens In5. Promoter fusions were used to show that the specific activator NunF is dependent on the global regulator of secondary metabolism GacA and is regulated by fungal-associated molecules and low temperatures. In contrast, GacA is stimulated by plant signal molecules leading to the hypothesis that P. fluorescens is a hyphosphere-associated bacterium carrying transcription factor genes that respond to signals indicating the presence of fungi and oomycetes. Based on these findings, we present a model for how synthesis of nunamycin and nunapeptin is regulated by fungal- and oomycete-associated molecules.IMPORTANCE Cyclic lipopeptide (CLP) synthesis gene clusters in pseudomonads display a high degree of synteny, and the structures of the peptides synthesized are very similar. Accordingly, the genomic island encoding the synthesis of syringomycin and syringopeptin in P. syringae pv. syringae closely resembles that of P. fluorescens In5, which contains genes coding for synthesis of the antifungal and anti-oomycete peptides nunamycin and nunapeptin, respectively. However, the regulation of syringomycin and syringopeptin synthesis is different from that of nunamycin and nunapeptin synthesis. While CLP synthesis in the plant pathogen P. syringae pv. syringae is induced by plant signal molecules, such compounds do not significantly influence synthesis of nunamycin and nunapeptin in P. fluorescens In5. Instead, fungal-associated molecules positively regulate antifungal peptide synthesis in P. fluorescens In5, while the synthesis of the global regulator GacA in P. fluorescens In5 is positively regulated by plant signal molecules but not fungal-associated molecules.
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Draft Genome Sequence of Bacillus velezensis BZR 336g, a Plant Growth-Promoting Antifungal Biocontrol Agent Isolated from Winter Wheat. Microbiol Resour Announc 2020; 9:9/30/e00450-20. [PMID: 32703828 PMCID: PMC7378027 DOI: 10.1128/mra.00450-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bacillus velezensis strain BZR 336g is a plant growth-promoting rhizobacterium isolated from a winter wheat rhizoplane from the Krasnodar region in Russia. In this study, we report the genome, including genes with known phenotypic function, i.e., the biosynthesis of secondary metabolites with fungicidal and plant growth-promoting activities. We sequenced and analyzed the complete BZR 336g genome using two different DNA preparation methods to help us better understand the origin of the antimicrobial and antifungal abilities and to weigh the biocontrol properties of this strain.
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12
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Kang SM, Bilal S, Shahzad R, Kim YN, Park CW, Lee KE, Lee JR, Lee IJ. Effect of Ammonia and Indole-3-acetic Acid Producing Endophytic Klebsiella pneumoniae YNA12 as a Bio-Herbicide for Weed Inhibition: Special Reference with Evening Primroses. PLANTS (BASEL, SWITZERLAND) 2020; 9:E761. [PMID: 32570708 PMCID: PMC7355527 DOI: 10.3390/plants9060761] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/12/2020] [Accepted: 06/12/2020] [Indexed: 11/23/2022]
Abstract
Information on the use of endophytic bacteria as a bio-herbicide for the management of weed control in agricultural fields is limited. The current study aimed to isolate endophytic bacteria from evening primroses and to screen them for their bio-herbicidal activity. Two isolated endophytic bacteria (Pantoea dispersa YNA11 and Klebsiella pneumoniae YNA12) were initially screened for citrate utilization and for indole-3-acetic acid (IAA) and catalase production. The preliminary biochemical assessment showed YNA12 as a positive strain. Ammonia, catalase, and IAA in its culture filtrate were quantified. Gas Chromatography/Mass Spectroscopy- Selective Ion Monitoring (GC/MS-SIM) analysis revealed the production of IAA by YNA12 in a time-dependent manner. YNA12 also exhibited significant ammonia-producing potential and catalase activity against hydrogen peroxide. The YNA12 culture filtrate significantly inhibited the germination rate of evening primrose seeds, resulting in a marked reduction in seedling length and biomass compared with those of the control seeds. Moreover, the culture filtrate of YNA12 significantly accelerated the endogenous abscisic acid (ABA) production and catalase activity of evening primrose seedlings. Macronutrient regulation was adversely affected in the seedlings exposed to the culture filtrate of YNA12, leading to inhibition of seed germination. The current results suggest that endophytic YNA12 may be used as a potent bio-herbicidal agent for controlling weed growth and development.
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Affiliation(s)
- Sang-Mo Kang
- Institute of Agricultural Science and Technology, Kyungpook National University, Daegu 41566, Korea;
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea; (Y.-N.K.); (C.-W.P.); (K.-E.L.)
| | - Saqib Bilal
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman;
| | - Raheem Shahzad
- Basic and Applied Scientific Research Center, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia;
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Yu-Na Kim
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea; (Y.-N.K.); (C.-W.P.); (K.-E.L.)
| | - Chang-Wook Park
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea; (Y.-N.K.); (C.-W.P.); (K.-E.L.)
| | - Ko-Eun Lee
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea; (Y.-N.K.); (C.-W.P.); (K.-E.L.)
| | - Jeong-Ran Lee
- Crop Protection Division, National Institute of Agricultural Science, RDA, Wanju 55365, Korea;
| | - In-Jung Lee
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea; (Y.-N.K.); (C.-W.P.); (K.-E.L.)
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13
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Wen T, Zhao M, Liu T, Huang Q, Yuan J, Shen Q. High abundance of Ralstonia solanacearum changed tomato rhizosphere microbiome and metabolome. BMC PLANT BIOLOGY 2020; 20:166. [PMID: 32293273 PMCID: PMC7160980 DOI: 10.1186/s12870-020-02365-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 03/26/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Rhizosphere microbiome is dynamic and influenced by environment factors surrounded including pathogen invasion. We studied the effects of Ralstonia solanacearum pathogen abundance on rhizosphere microbiome and metabolome by using high throughput sequencing and GC-MS technology. RESULTS There is significant difference between two rhizosphere bacterial communities of higher or lower pathogen abundance, and this difference of microbiomes was significant even ignoring the existence of pathogen. Higher pathogen abundance decreased the alpha diversity of rhizosphere bacterial community as well as connections in co-occurrence networks. Several bacterial groups such as Bacillus and Chitinophaga were negatively related to the pathogen abundance. The GC-MS analysis revealed significantly different metabolomes in two groups of rhizosphere soils, i.e., the rhizosphere soil of lower harbored more sugars such as fructose, sucrose and melibiose than that in high pathogen abundance. CONCLUSIONS The dissimilar metabolomes in two rhizosphere soils likely explained the difference of bacterial communities with Mantel test. Bacillus and Chitinophaga as well as sugar compounds negatively correlated with high abundance of pathogen indicated their potential biocontrol ability.
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Affiliation(s)
- Tao Wen
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mengli Zhao
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ting Liu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qiwei Huang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jun Yuan
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Qirong Shen
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, Nanjing, 210095, China
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Draft Genome Sequence of Pseudomonas sp. Strain LD120, Isolated from the Marine Alga Saccharina latissima. Microbiol Resour Announc 2020; 9:9/8/e01305-19. [PMID: 32079630 PMCID: PMC7033267 DOI: 10.1128/mra.01305-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the draft genome sequence of Pseudomonas sp. strain LD120, which was isolated from a brown macroalga in the Baltic Sea. The genome of this marine Pseudomonas protegens subgroup bacterium harbors biosynthetic gene clusters for toxic metabolites typically produced by members of this Pseudomonas subgroup, including 2,4-diacetylphloroglucinol, pyoluteorin, and rhizoxin analogs. We report the draft genome sequence of Pseudomonas sp. strain LD120, which was isolated from a brown macroalga in the Baltic Sea. The genome of this marine Pseudomonas protegens subgroup bacterium harbors biosynthetic gene clusters for toxic metabolites typically produced by members of this Pseudomonas subgroup, including 2,4-diacetylphloroglucinol, pyoluteorin, and rhizoxin analogs.
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