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Schlechter RO, Marti E, Remus-Emsermann MNP, Drissner D, Gekenidis MT. Correlation of in vitro biofilm formation capacity with persistence of antibiotic-resistant Escherichia coli on gnotobiotic lamb's lettuce. Appl Environ Microbiol 2025; 91:e0029925. [PMID: 40293242 DOI: 10.1128/aem.00299-25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2025] [Accepted: 03/31/2025] [Indexed: 04/30/2025] Open
Abstract
Bacterial contamination of fresh produce is a growing concern for food safety, as apart from human pathogens, antibiotic-resistant bacteria (ARB) can persist on fresh leafy produce. A prominent persistence trait in bacteria is biofilm formation, as it provides increased tolerance to stressful conditions. We screened a comprehensive collection of 174 antibiotic-susceptible and -resistant Escherichia coli originating from fresh leafy produce and its production environment. We tested the ability of these strains to produce biofilms, ranging from none or weak to extreme biofilm-forming bacteria. Next, we tested the ability of selected antibiotic-resistant isolates to colonize gnotobiotic lamb's lettuce (Valerianella locusta) plants. We hypothesized that a higher in vitro biofilm formation capacity correlates with increased colonization of gnotobiotic plant leaves. Despite a marked difference in the ability to form in vitro biofilms for a number of E. coli strains, in vitro biofilm formation was not associated with increased survival on gnotobiotic V. locusta leaf surfaces. However, all tested strains persisted for at least 21 days, highlighting potential food safety risks through unwanted ingestion of resistant bacteria. Population densities of biofilm-forming E. coli exhibited a complex pattern, with subpopulations more successful in colonizing gnotobiotic V. locusta leaves. These findings emphasize the complex behavior of ARB on leaf surfaces and their implications for human safety.IMPORTANCEEach raw food contains a collection of microorganisms, including bacteria. This is of special importance for fresh produce such as leafy salads or herbs, as these foods are usually consumed raw or after minimal processing, whereby higher loads of living bacteria are ingested than with a food that is heated before consumption. A common bacterial lifestyle involves living in large groups embedded in secreted protective substances. Such bacterial assemblies, so-called biofilms, confer high persistence and resistance of bacteria to external harsh conditions. In our research, we investigated whether stronger in vitro biofilm formation by antibiotic-resistant Escherichia coli correlates with better survival on lamb's lettuce leaves. Although no clear correlation was observed between biofilm formation capacity and population density on the salad, all tested isolates could survive for at least 3 weeks with no significant decline over time, highlighting a potential food safety risk independently of in vitro biofilm formation.
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Affiliation(s)
- Rudolf O Schlechter
- Institute of Microbiology, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Elisabet Marti
- Research Group Microbiological Food Safety, Agroscope, Bern, Switzerland
| | - Mitja N P Remus-Emsermann
- Institute of Microbiology, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - David Drissner
- Department of Life Sciences, Albstadt-Sigmaringen University, Sigmaringen, Germany
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2
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Elias J, Sharma V, Archana G, Kumar GN. Cra-controlled antisense RNA-downregulation of isocitrate dehydrogenase in Escherichia coli. Arch Microbiol 2025; 207:105. [PMID: 40167800 DOI: 10.1007/s00203-025-04290-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2025] [Revised: 02/24/2025] [Accepted: 02/26/2025] [Indexed: 04/02/2025]
Abstract
Catabolite repressor activator (Cra) protein (formerly called FruR) found in E. coli is known to regulate the expression of many genes positively and negatively in response to the intracellular levels of fructose-1-phosphate (F-1-P) and fructose-1,6-bisphopahate (F-1,6-bisP). In this paper, we report synthesis and characterization of a conditionally expressed antisense RNA corresponding to 101 bp of isocitrate dehydrogenase (icd) gene (as-icd) under Cra (FruR) responsive promoter fruB (PfruB as-icd construct denoted as pVS2K3) in E. coli K-12 derivative (DH5α) and E. coli B derivative (BL21) strains. Previous studies have shown that ICD mutants accumulated citrate intracellularly but failed to grow on glucose in absence of glutamate. Hence, a conditional downregulation of icd gene could be helpful in overcoming this lethality and also aid in understanding the flux towards citrate accumulation. Effect of pVS2K3 construct was monitored in E. coli DH5α and E. coli BL21 during growth on carbon sources wherein the fruB promoter is active (glucose) or repressed (glycerol). A 3-to 4-fold decrease in ICDH activity was observed in E. coli DH5α expressing pVS2K3 on glucose but no change in ICDH activity was observed in E. coli BL21 expressing pVS2K3 on glucose. This alteration could be attributed to the anomalous Cra regulation seen in E. coli B strain which could be a crucial factor while choosing PfruB promoter for expression studies.
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Affiliation(s)
- Jisha Elias
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390 002, India
- Medgenome Labs Ltd, Kailash Cancer Hospital and Research Centre, Goraj, Vadodara, Gujarat, 391760, India
| | - Vikas Sharma
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390 002, India.
- Department of Biotechnology, Ambala College of Engineering and Applied Research, Devsthali, Ambala Cantt-Jagadhari Road, P.O. Sambhalkha, Ambala, Haryana, 133101, India.
| | - G Archana
- Department of Microbiology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390 002, India
| | - G Naresh Kumar
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390 002, India.
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Barnes CJ, Bahram M, Nicolaisen M, Gilbert MTP, Vestergård M. Microbiome selection and evolution within wild and domesticated plants. Trends Microbiol 2025; 33:447-458. [PMID: 39701859 DOI: 10.1016/j.tim.2024.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2024] [Revised: 11/22/2024] [Accepted: 11/25/2024] [Indexed: 12/21/2024]
Abstract
Microbes are ubiquitously found across plant surfaces and even within their cells, forming the plant microbiome. Many of these microbes contribute to the functioning of the host and consequently affect its fitness. Therefore, in many contexts, including microbiome effects enables a better understanding of the phenotype of the plant rather than considering the genome alone. Changes in the microbiome composition are also associated with changes in the functioning of the host, and there has been considerable focus on how environmental variables regulate plant microbiomes. More recently, studies suggest that the host genome also preconditions the microbiome to the environment of the plant, and the microbiome is therefore subject to evolutionary forces. Here, we outline how plant microbiomes are governed by both environmental variables and evolutionary processes and how they can regulate plant health together.
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Affiliation(s)
- Christopher James Barnes
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark; Centre for Evolutionary Hologenomics, The Globe Institute, Faculty of Health, University of Copenhagen, Copenhagen, Denmark.
| | - Mo Bahram
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark; Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Ulls väg 16, 756 51, Sweden; Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St., 51005, Tartu, Estonia
| | - Mogens Nicolaisen
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
| | - M Thomas P Gilbert
- Centre for Evolutionary Hologenomics, The Globe Institute, Faculty of Health, University of Copenhagen, Copenhagen, Denmark; University Museum, NTNU, Trondheim, Norway
| | - Mette Vestergård
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
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4
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George AS, Simko I, Brandl MT. Escherichia coli O157:H7 multiplication in the latex of diverse lettuce genotypes is negatively correlated with plant peroxidase activity. Int J Food Microbiol 2025; 431:111095. [PMID: 39914144 DOI: 10.1016/j.ijfoodmicro.2025.111095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2024] [Revised: 01/23/2025] [Accepted: 02/04/2025] [Indexed: 02/19/2025]
Abstract
Lettuce (Lactuca spp.) is one of few edible plant species that produce latex. During lettuce harvest, latex leaks from ruptured laticifers onto the cut stem and adheres to other lettuce heads, harvesting tools, and packaging. Little is known about the colonization of lettuce latex by Shiga toxin-producing E. coli O157:H7 (EcO157), the main causal agent of outbreaks linked to lettuce. We screened 14 lettuce genotypes, including wild lettuce and commercial morphological types, for EcO157 multiplication in their latex-coated cut stems. Change in EcO157 density after its inoculation into the latex of these genotypes differed significantly and ranged from a 1.7× decline to a 3.6× increase over 6 h at 25 °C. EcO157 density increased in all genotypes except one, a romaine lettuce breeding line that caused decline of the pathogen. Latex biochemical properties, such as concentration of sucrose, glucose, fructose, phenolic compounds and H2O2, and peroxidase (POD) activity, were quantified in all genotypes. These traits varied significantly among genotypes, but only POD activity correlated significantly with the change of EcO157 density in the latex (r = -0.553). Total phenolics and H2O2 concentrations were also negatively and significantly correlated with each other (r = -0.608). The inhibitory effect of POD on EcO157 multiplication in lettuce latex and the identification of a genotype that causes decline of the pathogen in its latex may serve as new phenotypic and genotypic tools to control microbial contamination of lettuce at harvest. Their integration in lettuce breeding programs may enhance the microbial safety of lettuce.
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Affiliation(s)
- Andree S George
- Produce Safety and Microbiology Research Unit, US Department of Agriculture, Agricultural Research Service, Albany, CA, USA
| | - Ivan Simko
- Sam Farr United States Crop Improvement and Protection Research Center, US Department of Agriculture, Agricultural Research Service, Salinas, CA, USA
| | - Maria T Brandl
- Produce Safety and Microbiology Research Unit, US Department of Agriculture, Agricultural Research Service, Albany, CA, USA.
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Cowles KN, Iyer AS, McConnell I, Guillemette EG, Nellore D, Zaacks SC, Barak JD. Established Pseudomonas syringae pv. tomato infection disrupts immigration of leaf surface bacteria to the apoplast. Front Microbiol 2025; 16:1546411. [PMID: 39963495 PMCID: PMC11830748 DOI: 10.3389/fmicb.2025.1546411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2024] [Accepted: 01/21/2025] [Indexed: 02/20/2025] Open
Abstract
Bacterial disease alters the infection court creating new niches. The apoplast is an oasis from the hardships of the leaf surface and is generally inaccessible to nonpathogenic members of the phyllosphere bacterial community. Previously, we demonstrated that Salmonella enterica serovar Typhimurium (S. Typhimurium) immigrants to the leaf surface can both enter the apoplast and replicate due to conditions created by an established Xanthomonas hortorum pv. gardneri (Xhg) infection in tomato. Here, we have expanded our investigation of how infection changes the host by examining the effects of another water-soaking pathogen, Pseudomonas syringae pv. tomato (Pst), on immigrating bacteria. We discovered that, despite causing macroscopically similar symptoms as Xhg, Pst infection disrupts S. Typhimurium colonization of the apoplast. To determine if these effects were broadly applicable to phyllosphere bacteria, we examined the fates of immigrant Xhg and Pst arriving on an infected leaf. We found that this effect is not specific to S. Typhimurium, but that immigrating Xhg or Pst also struggled to fully join the infecting Pst population established in the apoplast. To identify the mechanisms underlying these results, we quantified macroscopic infection symptoms, examined stomata as a pinch point of bacterial entry, and characterized aspects of interbacterial competition. While it may be considered common knowledge that hosts are fundamentally altered following infection, the mechanisms that drive these changes remain poorly understood. Here, we investigated these pathogens to reach a deeper understanding of how infection alters a host from a rarely accessible, inhabitable environment to an obtainable, habitable niche.
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Affiliation(s)
- Kimberly N. Cowles
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Arjun S. Iyer
- Data Science Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Iain McConnell
- Data Science Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Ellie G. Guillemette
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Dharshita Nellore
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Sonia C. Zaacks
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Jeri D. Barak
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
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6
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Semenzato G, Vitali F, Frascella A, Lollini L, Mocali S, Papini A, Fani R, Emiliani G. Role of metabolism, resistance, and/or antagonism as drivers of endomicrobiomes assemblage in Origanum heracleoticum L. Commun Biol 2025; 8:158. [PMID: 39900981 PMCID: PMC11790966 DOI: 10.1038/s42003-025-07527-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 01/13/2025] [Indexed: 02/05/2025] Open
Abstract
The understanding of selective forces driving the compartmentalization of microbiota in plants remains limited. In this study, we performed a phenotypic characterization of bacterial endophytes isolated from the medicinal plant Origanum heracleoticum, together with the determination of the antibiotic resistance profiles and the antagonistic interactions of communities within and across different plant organs. Results revealed organ-related differences in the metabolic capabilities of bacteria, with those associated with stems displaying the highest metabolic activity for carbon sources. Contrarily, the patterns of antibiotic resistance appeared closely aligned with the taxonomical classification of the endophytes. The presence of antagonistic interactions, likely spurred by resource limitations, favor bacteria exhibiting greater metabolic plasticity. In conclusion, this research advances our comprehension of the intricate dynamics between plants and their associated microbiota, indicating that its composition is mainly influenced by forces contributing to the selection of distinct functions and phenotypic traits.
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Affiliation(s)
- Giulia Semenzato
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto Fiorentino, 50019, Florence, Italy
| | - Francesco Vitali
- Council for Agricultural Research and Economics (CREA) - Research Centre for Agriculture and Environment, Via di Lanciola 12/A, Cascine del Riccio, 50125, Florence, Italy
| | - Arcangela Frascella
- Institute of Biosciences and Bioresources (IBBR) - National Research Council (CNR), Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy.
| | - Ludovica Lollini
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto Fiorentino, 50019, Florence, Italy
| | - Stefano Mocali
- Council for Agricultural Research and Economics (CREA) - Research Centre for Agriculture and Environment, Via di Lanciola 12/A, Cascine del Riccio, 50125, Florence, Italy
| | - Alessio Papini
- Department of Biology, University of Florence, Via Micheli 3, 50121, Firenze, Italy
| | - Renato Fani
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto Fiorentino, 50019, Florence, Italy.
| | - Giovanni Emiliani
- Institute for Sustainable Plant Protection (IPSP) - National Research Council (CNR), Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy
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7
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Schlechter RO, Remus‐Emsermann MNP. Differential Responses of Methylobacterium and Sphingomonas Species to Multispecies Interactions in the Phyllosphere. Environ Microbiol 2025; 27:e70025. [PMID: 39792582 PMCID: PMC11722692 DOI: 10.1111/1462-2920.70025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2024] [Revised: 11/06/2024] [Accepted: 11/29/2024] [Indexed: 01/12/2025]
Abstract
The leaf surface, known as the phylloplane, presents an oligotrophic and heterogeneous environment due to its topography and uneven distribution of resources. Although it is a challenging environment, leaves support abundant bacterial communities that are spatially structured. However, the factors influencing these spatial distribution patterns are not well understood. To study the changes in population density and spatial distribution of bacteria in synthetic communities, the behaviour of two common bacterial groups in the Arabidopsis thaliana leaf microbiota-Methylobacterium (methylobacteria) and Sphingomonas (sphingomonads)-was examined. Using synthetic communities consisting of two or three species, the hypothesis was tested that the presence of a third species affects the density and spatial interaction of the other two species. Results indicated that methylobacteria exhibit greater sensitivity to changes in population densities and spatial patterns, with higher intra-genus competition and lower densities and aggregation compared to sphingomonads. Pairwise comparisons were insufficient to explain the shifts observed in three-species communities, suggesting that higher-order interactions influence the structuring of complex communities. This emphasises the role of multispecies interactions in determining spatial patterns and community dynamics on the phylloplane.
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Affiliation(s)
- R. O. Schlechter
- Institute of Microbiology and Dahlem Centre of Plant Sciences, Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
- School of Biological Sciences and Biomolecular Interaction Centre and Bioprotection Research CoreUniversity of CanterburyChristchurchNew Zealand
| | - M. N. P. Remus‐Emsermann
- Institute of Microbiology and Dahlem Centre of Plant Sciences, Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
- School of Biological Sciences and Biomolecular Interaction Centre and Bioprotection Research CoreUniversity of CanterburyChristchurchNew Zealand
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8
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Wang L, Liu Z, Bres C, Jin G, Fanin N. Coniferous Tree Species Identity and Leaf Aging Alter the Composition of Phyllosphere Communities Through Changes in Leaf Traits. MICROBIAL ECOLOGY 2024; 87:126. [PMID: 39382725 PMCID: PMC11464569 DOI: 10.1007/s00248-024-02440-w] [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: 06/21/2024] [Accepted: 10/01/2024] [Indexed: 10/10/2024]
Abstract
Phyllosphere microorganisms are essential for plant growth and health. Although there are an increasing number of studies showing that the composition of phyllosphere communities varies among different plant species, it remains unclear whether and how their bacterial and fungal community composition predictably varies with plant traits and leaf age. In this study, we used high-throughput sequencing to explore the diversity and composition of phyllosphere communities in needles of different ages (originating from different cohorts) for three evergreen coniferous species (Pinus koraiensis, Picea koraiensis, and Abies nephrolepis). Our results indicated that Gammaproteobacteria (bacteria) and Dothideomycetes (fungi) were dominant in newly formed needles, whereas Actinobacteria (bacteria) and Eurotiomycetes (fungi) were dominant in perennial needles. Tree species identity and needle age were the main factors explaining the variations of the α diversity (species richness of phyllosphere communities) and β diversity (dissimilarity among phyllosphere communities). In particular, we found that leaf dry matter content, leaf mass per area, and total phosphorus content emerged as key predictors of composition and diversity of phyllosphere microbial communities, underscoring the major influence of tree species identity and needle age on phyllosphere communities through changes in plant functional traits. Finally, we found that the interaction between tree species identity and needle age also contributed significantly to explaining the diversity and composition of phyllosphere communities, probably because differences in plant functional traits or environmental conditions between new and perennial needles depend on tree growth rates and resource acquisition strategies. These findings provide new insights into the mechanisms of community assembly among different evergreen tree species and offer a better understanding of the interactions between plant traits and phyllosphere microorganisms during needle aging.
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Affiliation(s)
- Lei Wang
- School of Ecology, Northeast Forestry University, Harbin, 150040, China
- UMR 1391 ISPA, INRAE, Bordeaux Sciences Agro, 71 Avenue Edouard Bourlaux, CS 20032, F33882, Villenave-d'Ornon Cedex, France
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin, 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Zhili Liu
- School of Ecology, Northeast Forestry University, Harbin, 150040, China.
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin, 150040, China.
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China.
| | - Cécile Bres
- UMR 1391 ISPA, INRAE, Bordeaux Sciences Agro, 71 Avenue Edouard Bourlaux, CS 20032, F33882, Villenave-d'Ornon Cedex, France
| | - Guangze Jin
- School of Ecology, Northeast Forestry University, Harbin, 150040, China
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin, 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Nicolas Fanin
- UMR 1391 ISPA, INRAE, Bordeaux Sciences Agro, 71 Avenue Edouard Bourlaux, CS 20032, F33882, Villenave-d'Ornon Cedex, France
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9
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Fourie JCJ, Van Wyk D, Bezuidenhout CC, Mienie C, Adeleke R. The effects of irrigation on the survival of Clostridium sporogenes in the phyllosphere and soil environments of lettuce. 3 Biotech 2024; 14:239. [PMID: 39310030 PMCID: PMC11415320 DOI: 10.1007/s13205-024-04069-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 08/26/2024] [Indexed: 09/25/2024] Open
Abstract
This study aimed to address the gap in knowledge regarding the fate of foodborne pathogens within agro-ecosystems. It specifically focused on the surrogate microorganism Clostridium sporogenes, which was introduced into lettuce-producing environments via surface and spray irrigation methods, respectively. The concentration of C. sporogenes in the rhizosphere, phyllosphere, and non-rhizosphere soil was quantified by quantitative polymerase chain reaction (qPCR) over a 42-day trial. The surface irrigation method exhibited a more noticeable contamination effect on the soil environments, compared to the phyllosphere. The results indicated a noticeable increase in C. sporogenes concentrations during the initial 22 days, with a 10.4-fold rise (0.39-4.05 log copy numbers/g soil) in the rhizosphere and 1.9-fold increase (2.97-5.59 log copy numbers/g soil) in the non-rhizosphere. However, concentrations in both soil environments subsequently decreased, falling below the initial inoculum concentration by the end of the trial. In contrast, the spray irrigation method resulted in most of the contamination being localised on the lettuce phyllosphere, with a high C. sporogenes concentration of 9.09 log copy numbers/g leaves on day 0. This concentration exponentially decreased to a minimal 0.019 log copy numbers/g leaves by day 32. Although concentrations in both soil environments decreased over time, trace concentrations of C. sporogenes were detectable at the end of the trial, posing a potential hazard to the microbiological safety of postharvest produce. These findings shed light on the dynamics of C. sporogenes in agro-ecosystems and underscore the importance of irrigation practices that ensure the safety of those who consume fresh produce. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-024-04069-5.
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Affiliation(s)
| | - Deidre Van Wyk
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | | | - Charlotte Mienie
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Rasheed Adeleke
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
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10
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Thomas G, Kay WT, Fones HN. Life on a leaf: the epiphyte to pathogen continuum and interplay in the phyllosphere. BMC Biol 2024; 22:168. [PMID: 39113027 PMCID: PMC11304629 DOI: 10.1186/s12915-024-01967-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 08/01/2024] [Indexed: 08/11/2024] Open
Abstract
Epiphytic microbes are those that live for some or all of their life cycle on the surface of plant leaves. Leaf surfaces are a topologically complex, physicochemically heterogeneous habitat that is home to extensive, mixed communities of resident and transient inhabitants from all three domains of life. In this review, we discuss the origins of leaf surface microbes and how different biotic and abiotic factors shape their communities. We discuss the leaf surface as a habitat and microbial adaptations which allow some species to thrive there, with particular emphasis on microbes that occupy the continuum between epiphytic specialists and phytopathogens, groups which have considerable overlap in terms of adapting to the leaf surface and between which a single virulence determinant can move a microbial strain. Finally, we discuss the recent findings that the wheat pathogenic fungus Zymoseptoria tritici spends a considerable amount of time on the leaf surface, and ask what insights other epiphytic organisms might provide into this pathogen, as well as how Z. tritici might serve as a model system for investigating plant-microbe-microbe interactions on the leaf surface.
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Affiliation(s)
| | - William T Kay
- Department of Plant Sciences, University of Oxford, Oxford, UK
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11
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Yu T, Liu Z, Hu B, Zhu L. Field-based investigation reveals selective enrichment of companion microbes in vegetables leading to specific accumulation of antibiotic resistance genes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 929:172636. [PMID: 38653418 DOI: 10.1016/j.scitotenv.2024.172636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
Vegetables capture antibiotic resistance genes (ARGs) from the soil and then pass them on to consumers through the delivery chain and food chain, and are therefore the key node that may increase the risk of human exposure to ARGs. This study investigates the patterns and driving forces behind the transmission of ARGs from soil to vegetables by the commonly planted cash crops in the coastal region of southern China, i.e. broccoli, pumpkin, and broad bean, to investigate. The study used metagenomic data to reveal the microbial and ARGs profiles of various vegetables and the soil they are grown. The results indicate significant differences in the accumulation of ARGs among different vegetables harvested in the same area at the same time frame, and the ARGs accumulation ability of the three vegetables was in the order of broccoli, broad bean, and pumpkin. In addition, broccoli collected the highest number of ARGs in types (n = 14), while pumpkin (n = 13) does not obtain trimethoprim resistance genes and broad beans (n = 10) do not obtain chloramphenicol, fosmidomycin, quinolone, rifamycin, or trimethoprim resistance genes. Host tracking analysis shows a strong positive correlation (|rho| > 0.8, p < 0.05) between enriched ARGs and plant companion microbes. Enrichment analysis of metabolic pathways of companion microbes shows that vegetables exhibit a discernible enrichment of companion microbes, with significant differences among vegetables. This phenomenon is primarily due to the screening of carbohydrate metabolism capabilities among companion microbes and leads varied patterns of ARGs that spread from the soil to vegetables. This offers a novel insight into the intervention of foodborne transmission of ARGs.
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Affiliation(s)
- Tao Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Zishu Liu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Baolan Hu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Lizhong Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China.
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12
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Ding Q, Gu G, Nou X, Micallef SA. Cultivar was more influential than bacterial strain and other experimental factors in recovery of Escherichia coli O157:H7 populations from inoculated live Romaine lettuce plants. Microbiol Spectr 2024; 12:e0376723. [PMID: 38363139 PMCID: PMC10986467 DOI: 10.1128/spectrum.03767-23] [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] [Received: 10/24/2023] [Accepted: 01/22/2024] [Indexed: 02/17/2024] Open
Abstract
The varied choice of bacterial strain, plant cultivar, and method used to inoculate, retrieve, and enumerate Escherichia coli O157:H7 from live plants could affect comparability among studies evaluating lettuce-enterobacterial interactions. Cultivar, bacterial strain, incubation time, leaf side inoculated, and sample processing method were assessed for their influence in recovering and quantifying E. coli O157:H7 from live Romaine lettuce. Cultivar exerted the strongest effect on E. coli O157:H7 counts, which held up even when cultivar was considered in interactions with other factors. Recovery from the popularly grown green Romaine "Rio Bravo" was higher than from the red variety "Outredgeous." Other modulating variables were incubation time, strain, and leaf side inoculated. Sample processing method was not significant. Incubation for 24 hours post-lettuce inoculation yielded greater counts than 48 hours, but was affected by lettuce cultivar, bacterial strain, and leaf side inoculated. Higher counts obtained for strain EDL933 compared to a lettuce outbreak strain 2705C emphasized the importance of selecting relevant strains for the system being studied. Inoculating the abaxial side of leaves gave higher counts than adaxial surface inoculation, although this factor interacted with strain and incubation period. Our findings highlight the importance of studying interactions between appropriate bacterial strains and plant cultivars for more relevant research results, and of standardizing inoculation and incubation procedures. The strong effect of cultivar exerted on the E. coli O157:H7-lettuce association supports the need to start reporting cultivar information for illness outbreaks to facilitate the identification and study of plant traits that impact food safety risk.IMPORTANCEThe contamination of Romaine lettuce with Escherichia coli O157:H7 has been linked to multiple foodborne disease outbreaks, but variability in the methods used to evaluate E. coli O157:H7 association with live lettuce plants complicates the comparability of different studies. In this study, various experimental variables and sample processing methods for recovering and quantifying E. coli O157:H7 from live Romaine lettuce were assessed. Cultivar was found to exert the strongest influence on E. coli O157:H7 retrieval from lettuce. Other modulating factors were bacterial incubation time on plants, strain, and leaf side inoculated, while sample processing method had no impact. Our findings highlight the importance of selecting relevant cultivars and strains, and of standardizing inoculation and incubation procedures, in these types of assessments. Moreover, results support the need to start reporting cultivars implicated in foodborne illness outbreaks to facilitate the identification and study of plant traits that impact food safety risk.
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Affiliation(s)
- Qiao Ding
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
| | - Ganyu Gu
- Environmental Microbial and Food Safety Laboratory, USDA ARS, Beltsville, Maryland, USA
| | - Xiangwu Nou
- Environmental Microbial and Food Safety Laboratory, USDA ARS, Beltsville, Maryland, USA
| | - Shirley A. Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
- Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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13
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Xiao J, Sun S, Liu Z, Fan C, Zhu B, Zhang D. Analysis of key genes for the survival of Pantoea agglomerans under nutritional stress. Int J Biol Macromol 2023; 253:127059. [PMID: 37769756 DOI: 10.1016/j.ijbiomac.2023.127059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 09/13/2023] [Accepted: 09/18/2023] [Indexed: 10/03/2023]
Abstract
The absolute amount of nutrients on plant leaves is usually low, and the growth of epiphytic bacteria is typically limited by nutrient content. Thus, is of great significance to study the survival mechanism of epiphytes under nutritional stress for plant disease control. In this paper, Pantoea agglomerans CHTF15 isolated from walnut leaves was used to detect the key genes for the survival of the bacterium under simulated nutrient stress in artificial medium. Genome sequencing was combined with transposon insertion sequencing (Tn-seq) for the detection technique. A total of 105 essential genes were screened from the whole genome. The genes were mainly related to the nucleotide metabolism, protein metabolism, biological oxidation and the gene repair of bacteria analyzed by gene ontology (GO) enrichment analysis. Volcano map analysis demonstrated that the functions of the 15 genes with the most significant differences were generally related to the synthesis of amino acids or proteins, the nucleotide metabolism and homologous recombination and repair. Competitive index analysis revealed that the deletion of the genes dksA and epmA regulating protein synthesis, the gene ribB involved in the nucleotide metabolism and the gene xerD involved in recombination repair induced a significant reduction in the survival ability of the corresponding mutants in the 0.10 % YEP medium and the walnut leaf surface. The results act as a foundation for further in-depth research on the infection process and the mechanisms of pathogenic bacteria.
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Affiliation(s)
- Jiawen Xiao
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China
| | - Shangyi Sun
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China
| | - Zhaosha Liu
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China
| | - Chenxi Fan
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China
| | - Baocheng Zhu
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China
| | - Dongdong Zhang
- College of Life Science, Hebei Agricultural University, Baoding, China; Hebei Provincial Engineering Research Center for Resource Utilization of Agricultural Wastes, Baoding, China.
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14
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Anderson JC. Ill Communication: Host Metabolites as Virulence-Regulating Signals for Plant-Pathogenic Bacteria. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:49-71. [PMID: 37253693 DOI: 10.1146/annurev-phyto-021621-114026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plant bacterial pathogens rely on host-derived signals to coordinate the deployment of virulence factors required for infection. In this review, I describe how diverse plant-pathogenic bacteria detect and respond to plant-derived metabolic signals for the purpose of virulence gene regulation. I highlight examples of how pathogens perceive host metabolites through membrane-localized receptors as well as intracellular response mechanisms. Furthermore, I describe how individual strains may coordinate their virulence using multiple distinct host metabolic signals, and how plant signals may positively or negatively regulate virulence responses. I also describe how plant defenses may interfere with the perception of host metabolites as a means to dampen pathogen virulence. The emerging picture is that recognition of host metabolic signals for the purpose of virulence gene regulation represents an important primary layer of interaction between pathogenic bacteria and host plants that shapes infection outcomes.
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Affiliation(s)
- Jeffrey C Anderson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA;
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15
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Schlechter RO, Kear EJ, Bernach M, Remus DM, Remus-Emsermann MNP. Metabolic resource overlap impacts competition among phyllosphere bacteria. THE ISME JOURNAL 2023; 17:1445-1454. [PMID: 37355740 PMCID: PMC10432529 DOI: 10.1038/s41396-023-01459-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023]
Abstract
The phyllosphere is densely colonised by microbial communities, despite sparse and heterogeneously distributed resources. The limitation of resources is expected to drive bacterial competition resulting in exclusion or coexistence based on fitness differences and resource overlap between individual colonisers. We studied the impact of resource competition by determining the effects of different bacterial colonisers on the growth of the model epiphyte Pantoea eucalypti 299R (Pe299R). Resource overlap was predicted based on genome-scale metabolic modelling. By combining results of metabolic modelling and pairwise competitions in the Arabidopsis thaliana phyllosphere and in vitro, we found that ten resources sufficed to explain fitness of Pe299R. An effect of both resource overlap and phylogenetic relationships was found on competition outcomes in vitro as well as in the phyllosphere. However, effects of resource competition were much weaker in the phyllosphere when compared to in vitro experiments. When investigating growth dynamics and reproductive success at the single-cell resolution, resource overlap and phylogenetic relationships are only weakly correlated with epiphytic Pe299R reproductive success, indicating that the leaf's spatial heterogeneity mitigates resource competition. Although the correlation is weak, the presence of competitors led to the development of Pe299R subpopulations that experienced different life histories and cell divisions. In some in planta competitions, Pe299R benefitted from the presence of epiphytes despite high resource overlap to the competitor strain suggesting other factors having stronger effects than resource competition. This study provides fundamental insights into how bacterial communities are shaped in heterogeneous environments and a framework to predict competition outcomes.
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Affiliation(s)
- Rudolf O Schlechter
- Institute of Microbiology and Dahlem Centre of Plant Sciences, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany.
- School of Biological Sciences, University of Canterbury, Christchurch, 8011, New Zealand.
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, 8011, New Zealand.
- Bioprotection Research Core, University of Canterbury, Christchurch, 8011, New Zealand.
| | - Evan J Kear
- School of Biological Sciences, University of Canterbury, Christchurch, 8011, New Zealand
| | - Michał Bernach
- Institute of Microbiology and Dahlem Centre of Plant Sciences, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
- School of Biological Sciences, University of Canterbury, Christchurch, 8011, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, 8011, New Zealand
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, 8011, New Zealand
| | - Daniela M Remus
- Protein Science and Engineering, Callaghan Innovation, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Mitja N P Remus-Emsermann
- Institute of Microbiology and Dahlem Centre of Plant Sciences, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany.
- School of Biological Sciences, University of Canterbury, Christchurch, 8011, New Zealand.
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, 8011, New Zealand.
- Bioprotection Research Core, University of Canterbury, Christchurch, 8011, New Zealand.
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16
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Demarquest G, Lajoie G. Bacterial endophytes of sugar maple leaves vary more idiosyncratically than epiphytes across a large geographic area. FEMS Microbiol Ecol 2023; 99:fiad079. [PMID: 37442613 DOI: 10.1093/femsec/fiad079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/15/2023] Open
Abstract
Bacteria from the leaf surface and the leaf tissue have been attributed with several beneficial properties for their plant host. Though physically connected, the microbial ecology of these compartments has mostly been studied separately such that we lack an integrated understanding of the processes shaping their assembly. We sampled leaf epiphytes and endophytes from the same individuals of sugar maple across the northern portion of its range to evaluate if their community composition was driven by similar processes within and across populations differing in plant traits and overall abiotic environment. Leaf compartment explained most of the variation in community diversity and composition across samples. Leaf epiphytic communities were driven more by host and site characteristics than endophytic communities, whose community composition was more idiosyncratic across samples. Our results suggest a greater importance of priority effects and opportunistic colonization in driving community assembly of leaf endophytes. Understanding the comparative assembly of bacterial communities at the surface and inside plant leaves may be particularly useful for leveraging their respective potential for improving the health of plants in natural and anthropized ecosystems.
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Affiliation(s)
- Garance Demarquest
- Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 rue Sherbrooke E, H1X 2B2 Montréal, Canada
- Université de Rennes, Agro-Campus Ouest, 65 Rue de Saint-Brieuc, 35042 Rennes, France
| | - Geneviève Lajoie
- Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 rue Sherbrooke E, H1X 2B2 Montréal, Canada
- Jardin Botanique de Montréal, 4101 rue Sherbrooke E, H1X 2B2 Montréal, Canada
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17
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Huang S, Zha X, Fu G. Affecting Factors of Plant Phyllosphere Microbial Community and Their Responses to Climatic Warming-A Review. PLANTS (BASEL, SWITZERLAND) 2023; 12:2891. [PMID: 37631103 PMCID: PMC10458011 DOI: 10.3390/plants12162891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/02/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023]
Abstract
Phyllosphere microorganisms are not only an important part of plants, but also an important part of microorganisms. In this review, the function of phyllosphere microorganisms, the assembly mechanism of phyllosphere microorganisms, the driving factors of phyllosphere microbial community structure, and the effects of climate warming on phyllosphere microbial community structure were reviewed. Generally, phyllosphere microorganisms have a variety of functions (e.g., fixing nitrogen, promoting plant growth). Although selection and dispersal processes together regulate the assembly of phyllospheric microbial communities, which one of the ecological processes is dominant and how external disturbances alter the relative contributions of each ecological process remains controversial. Abiotic factors (e.g., climatic conditions, geographical location and physical and chemical properties of soil) and biological factors (e.g., phyllosphere morphological structure, physiological and biochemical characteristics, and plant species and varieties) can affect phyllosphere microbial community structure. However, the predominant factors affecting phyllosphere microbial community structure are controversial. Moreover, how climate warming affects the phyllosphere microbial community structure and its driving mechanism have not been fully resolved, and further relevant studies are needed.
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Affiliation(s)
- Shaolin Huang
- Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
| | - Xinjie Zha
- Xi’an University of Finance and Economics, Xi’an 710100, China;
| | - Gang Fu
- Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
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18
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Schäfer M, Pacheco AR, Künzler R, Bortfeld-Miller M, Field CM, Vayena E, Hatzimanikatis V, Vorholt JA. Metabolic interaction models recapitulate leaf microbiota ecology. Science 2023; 381:eadf5121. [PMID: 37410834 DOI: 10.1126/science.adf5121] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 05/18/2023] [Indexed: 07/08/2023]
Abstract
Resource allocation affects the structure of microbiomes, including those associated with living hosts. Understanding the degree to which this dependency determines interspecies interactions may advance efforts to control host-microbiome relationships. We combined synthetic community experiments with computational models to predict interaction outcomes between plant-associated bacteria. We mapped the metabolic capabilities of 224 leaf isolates from Arabidopsis thaliana by assessing the growth of each strain on 45 environmentally relevant carbon sources in vitro. We used these data to build curated genome-scale metabolic models for all strains, which we combined to simulate >17,500 interactions. The models recapitulated outcomes observed in planta with >89% accuracy, highlighting the role of carbon utilization and the contributions of niche partitioning and cross-feeding in the assembly of leaf microbiomes.
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Affiliation(s)
- Martin Schäfer
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Alan R Pacheco
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Rahel Künzler
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | | | | | - Evangelia Vayena
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Vassily Hatzimanikatis
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
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19
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Cuellar-Gaviria TZ, García-Botero C, Ju KS, Villegas-Escobar V. The genome of Bacillus tequilensis EA-CB0015 sheds light into its epiphytic lifestyle and potential as a biocontrol agent. Front Microbiol 2023; 14:1135487. [PMID: 37051516 PMCID: PMC10083409 DOI: 10.3389/fmicb.2023.1135487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/06/2023] [Indexed: 03/29/2023] Open
Abstract
Different Bacillus species have successfully been used as biopesticides against a broad range of plant pathogens. Among these, Bacillus tequilensis EA-CB0015 has shown to efficiently control Black sigatoka disease in banana plants, presumably by mechanisms of adaptation that involve modifying the phyllosphere environment. Here, we report the complete genome of strain EA-CB0015, its precise taxonomic identity, and determined key genetic features that may contribute to its effective biocontrol of plant pathogens. We found that B. tequilensis EA-CB0015 harbors a singular 4 Mb circular chromosome, with 3,951 protein-coding sequences. Multi-locus sequence analysis (MLSA) and average nucleotide identity (ANI) analysis classified strain EA-CB0015 as B. tequilensis. Encoded within its genome are biosynthetic gene clusters (BGCs) for surfactin, iturin, plipastatin, bacillibactin, bacilysin, subtilosin A, sporulation killing factor, and other natural products that may facilitate inter-microbial warfare. Genes for indole-acetic acid (IAA) synthesis, the use of diverse carbon sources, and a multicellular lifestyle involving motility, biofilm formation, quorum sensing, competence, and sporulation suggest EA-CB0015 is adept at colonizing plant surfaces. Defensive mechanisms to survive invading viral infections and preserve genome integrity include putative type I and type II restriction modification (RM) and toxin/antitoxin (TA) systems. The presence of bacteriophage sequences, genomic islands, transposable elements, virulence factors, and antibiotic resistance genes indicate prior occurrences of genetic exchange. Altogether, the genome of EA-CB0015 supports its function as a biocontrol agent against phytopathogens and suggest it has adapted to thrive within phyllosphere environments.
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Affiliation(s)
- Tatiana Z. Cuellar-Gaviria
- CIBIOP Group, Department of Biological Sciences, Universidad EAFIT, Medellin, Colombia
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
- Banana Research Center, Augura, Conjunto Residencial Los Almendros, Carepa, Colombia
| | - Camilo García-Botero
- CIBIOP Group, Department of Biological Sciences, Universidad EAFIT, Medellin, Colombia
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH, United States
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
- *Correspondence: Kou-San Ju, ; Valeska Villegas-Escobar,
| | - Valeska Villegas-Escobar
- CIBIOP Group, Department of Biological Sciences, Universidad EAFIT, Medellin, Colombia
- *Correspondence: Kou-San Ju, ; Valeska Villegas-Escobar,
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20
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Liu X, Li Y, Micallef SA. Natural variation and drought-induced differences in metabolite profiles of red oak-leaf and Romaine lettuce play a role in modulating the interaction with Salmonella enterica. Int J Food Microbiol 2023; 385:109998. [PMID: 36371998 DOI: 10.1016/j.ijfoodmicro.2022.109998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/14/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022]
Abstract
Nutrients on produce surfaces are vital for successful enteric pathogen colonisation. In this study, we investigated natural variation in metabolite profiles of Romaine 'Parris Island Cos' and red oak-leaf lettuce 'Mascara' under regular and restricted watering conditions. We also investigated the impact of plant drought stress on the Salmonella - lettuce association. Salmonella Newport and Typhimurium were able to persist at higher levels on regularly watered Romaine than red oak-leaf lettuce. Drought treatment to lettuce impaired epiphytic Salmonella association, with S. Newport and Typhimurium being differentially affected. A higher log reduction of both serotypes was measured on drought-subjected red oak-leaf lettuce plants than controls, but S. Typhimurium was unaffected on water deficit-treated Romaine lettuce (p < 0.05). To assess Salmonella interaction with leaf surface metabolites, leaf washes collected from both cultivars were inoculated and found to be able to support S. Newport growth, with higher levels of Salmonella retrieved from Romaine washes (p < 0.05). The lag phase of S. Newport in washes from water restricted red oak-leaf lettuce was prolonged in relation to regularly-watered controls (p < 0.05). Untargeted plant metabolite profiling using electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) revealed natural variation between Romaine and red oak-leaf lettuce profiles for leaf tissue and leaf washes. Metabolite profile shifts were detected in both lettuce types in response to drought stress, but more unique peaks were detected in red oak-leaf than Romaine lettuce after drought treatment. Variation between the two cultivars was in part attributed to naturally higher levels of flavonoids and anthocyanins in red oak-leaf lettuce compared to Romaine. Moreover, red oak-leaf, but not Romaine lettuce, responded to drought by inducing the accumulation of proline, phenolics, flavonoids and anthocyanins. Drought stress, therefore, enhanced the functional food properties of red oak-leaf lettuce. Salmonella growth dynamics in lettuce leaf washes suggested that natural variation and drought-induced changes in metabolite profiles in lettuce could partly explain the differential susceptibility of various lettuce types to Salmonella, although the primary or secondary metabolites mediating this effect remain unknown. Regulated mild water stress should be investigated as an approach to lower Salmonella contamination risk in suitable lettuce cultivars, while simultaneously boosting the health beneficial quality of lettuce.
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Affiliation(s)
- Xingchen Liu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Yue Li
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, USA
| | - Shirley A Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD, USA.
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21
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Xanthomonas
Infection Transforms the Apoplast into an Accessible and Habitable Niche for Salmonella enterica. Appl Environ Microbiol 2022; 88:e0133022. [PMID: 36314834 PMCID: PMC9680631 DOI: 10.1128/aem.01330-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial spot disease caused by
Xanthomonas
species devastates tomato production worldwide. Salmonellosis outbreaks from consumption of raw produce have been linked to the arrival of
Salmonella enterica
on crop plants in the field via contaminated irrigation water.
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22
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Tripathi A, Pandey P, Tripathi SN, Kalra A. Perspectives and potential applications of endophytic microorganisms in cultivation of medicinal and aromatic plants. FRONTIERS IN PLANT SCIENCE 2022; 13:985429. [PMID: 36247631 PMCID: PMC9560770 DOI: 10.3389/fpls.2022.985429] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Ensuring food and nutritional security, it is crucial to use chemicals in agriculture to boost yields and protect the crops against biotic and abiotic perturbations. Conversely, excessive use of chemicals has led to many deleterious effects on the environment like pollution of soil, water, and air; loss of soil fertility; and development of pest resistance, and is now posing serious threats to biodiversity. Therefore, farming systems need to be upgraded towards the use of biological agents to retain agricultural and environmental sustainability. Plants exhibit a huge and varied niche for endophytic microorganisms inside the planta, resulting in a closer association between them. Endophytic microorganisms play pivotal roles in plant physiological and morphological characteristics, including growth promotion, survival, and fitness. Their mechanism of action includes both direct and indirect, such as mineral phosphate solubilization, fixating nitrogen, synthesis of auxins, production of siderophore, and various phytohormones. Medicinal and aromatic plants (MAPs) hold a crucial position worldwide for their valued essential oils and several phytopharmaceutically important bioactive compounds since ancient times; conversely, owing to the high demand for natural products, commercial cultivation of MAPs is on the upswing. Furthermore, the vulnerability to various pests and diseases enforces noteworthy production restraints that affect both crop yield and quality. Efforts have been made towards enhancing yields of plant crude drugs by improving crop varieties, cell cultures, transgenic plants, etc., but these are highly cost-demanding and time-consuming measures. Thus, it is essential to evolve efficient, eco-friendly, cost-effective simpler approaches for improvement in the yield and health of the plants. Harnessing endophytic microorganisms as biostimulants can be an effective and alternative step. This review summarizes the concept of endophytes, their multidimensional interaction inside the host plant, and the salient benefits associated with endophytic microorganisms in MAPs.
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Affiliation(s)
- Arpita Tripathi
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Faculty of Education, Teerthanker Mahaveer University, Moradabad, India
| | - Praveen Pandey
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Shakti Nath Tripathi
- Department of Botany, Nehru Gram Bharati Deemed to be University, Prayagraj, India
| | - Alok Kalra
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
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23
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Dundas CM, Dinneny JR. Genetic Circuit Design in Rhizobacteria. BIODESIGN RESEARCH 2022; 2022:9858049. [PMID: 37850138 PMCID: PMC10521742 DOI: 10.34133/2022/9858049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/31/2022] [Indexed: 10/19/2023] Open
Abstract
Genetically engineered plants hold enormous promise for tackling global food security and agricultural sustainability challenges. However, construction of plant-based genetic circuitry is constrained by a lack of well-characterized genetic parts and circuit design rules. In contrast, advances in bacterial synthetic biology have yielded a wealth of sensors, actuators, and other tools that can be used to build bacterial circuitry. As root-colonizing bacteria (rhizobacteria) exert substantial influence over plant health and growth, genetic circuit design in these microorganisms can be used to indirectly engineer plants and accelerate the design-build-test-learn cycle. Here, we outline genetic parts and best practices for designing rhizobacterial circuits, with an emphasis on sensors, actuators, and chassis species that can be used to monitor/control rhizosphere and plant processes.
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Affiliation(s)
| | - José R. Dinneny
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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24
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Gouka L, Vogels C, Hansen LH, Raaijmakers JM, Cordovez V. Genetic, Phenotypic and Metabolic Diversity of Yeasts From Wheat Flag Leaves. FRONTIERS IN PLANT SCIENCE 2022; 13:908628. [PMID: 35873980 PMCID: PMC9301128 DOI: 10.3389/fpls.2022.908628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
The phyllosphere, the aboveground part of a plant, is a harsh environment with diverse abiotic and biotic stresses, including oscillating nutrient availability and temperature as well as exposure to UV radiation. Microbial colonization of this dynamic environment requires specific adaptive traits, including tolerance to fluctuating temperatures, the production of secondary metabolites and pigments to successfully compete with other microorganisms and to withstand abiotic stresses. Here, we isolated 175 yeasts, comprising 15 different genera, from the wheat flag leaf and characterized a selection of these for various adaptive traits such as substrate utilization, tolerance to different temperatures, biofilm formation, and antagonism toward the fungal leaf pathogen Fusarium graminearum. Collectively our results revealed that the wheat flag leaf is a rich resource of taxonomically and phenotypically diverse yeast genera that exhibit various traits that can contribute to survival in the harsh phyllosphere environment.
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Affiliation(s)
- Linda Gouka
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Caroline Vogels
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Lars H. Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jos M. Raaijmakers
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
- Institute of Biology, Leiden, Netherlands
| | - Viviane Cordovez
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
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Micci A, Zhang Q, Chang X, Kingsley K, Park L, Chiaranunt P, Strickland R, Velazquez F, Lindert S, Elmore M, Vines PL, Crane S, Irizarry I, Kowalski KP, Johnston-Monje D, White JF. Histochemical Evidence for Nitrogen-Transfer Endosymbiosis in Non-Photosynthetic Cells of Leaves and Inflorescence Bracts of Angiosperms. BIOLOGY 2022; 11:biology11060876. [PMID: 35741397 PMCID: PMC9220352 DOI: 10.3390/biology11060876] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/15/2022] [Accepted: 06/01/2022] [Indexed: 12/13/2022]
Abstract
Simple Summary We used light and confocal microscopy to visualize bacteria in leaf and bract cells of more than 30 species in 18 families of seed plants. We detected chemical exchanges between intracellular bacteria and plant cells. We found that endophytic bacteria that show evidence of the transfer of nitrogen to plants are present in non-photosynthetic cells of leaves and bracts of diverse plant species. Nitrogen transfer from bacteria was observed in epidermal cells, various filamentous and glandular trichomes, and other non-photosynthetic cells. The most efficient of the nitrogen-transfer endosymbioses were seen to involve glandular trichomes, as seen in hops (Humulus lupulus) and hemp (Cannabis sativa). Trichome chemistry is hypothesized to function to scavenge oxygen around bacteria to facilitate nitrogen fixation. Abstract We used light and confocal microscopy to visualize bacteria in leaf and bract cells of more than 30 species in 18 families of seed plants. Through histochemical analysis, we detected hormones (including ethylene and nitric oxide), superoxide, and nitrogenous chemicals (including nitric oxide and nitrate) around bacteria within plant cells. Bacteria were observed in epidermal cells, various filamentous and glandular trichomes, and other non-photosynthetic cells. Most notably, bacteria showing nitrate formation based on histochemical staining were present in glandular trichomes of some dicots (e.g., Humulus lupulus and Cannabis sativa). Glandular trichome chemistry is hypothesized to function to scavenge oxygen around bacteria and reduce oxidative damage to intracellular bacterial cells. Experiments to assess the differential absorption of isotopic nitrogen into plants suggest the assimilation of nitrogen into actively growing tissues of plants, where bacteria are most active and carbohydrates are more available. The leaf and bract cell endosymbiosis types outlined in this paper have not been previously reported and may be important in facilitating plant growth, development, oxidative stress resistance, and nutrient absorption into plants. It is unknown whether leaf and bract cell endosymbioses are significant in increasing the nitrogen content of plants. From the experiments that we conducted, it is impossible to know whether plant trichomes evolved specifically as organs for nitrogen fixation or if, instead, trichomes are structures in which bacteria easily colonize and where some casual nitrogen transfer may occur between bacteria and plant cells. It is likely that the endosymbioses seen in leaves and bracts are less efficient than those of root nodules of legumes in similar plants. However, the presence of endosymbioses that yield nitrate in plants could confer a reduced need for soil nitrogen and constitute increased nitrogen-use efficiency, even if the actual amount of nitrogen transferred to plant cells is small. More research is needed to evaluate the importance of nitrogen transfer within leaf and bract cells of plants.
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Affiliation(s)
- April Micci
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
- Correspondence: (A.M.); (J.F.W.); Tel.: +848-932-6286 (J.F.W.)
| | - Qiuwei Zhang
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Xiaoqian Chang
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Kathryn Kingsley
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Linsey Park
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Peerapol Chiaranunt
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Raquele Strickland
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Fernando Velazquez
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Sean Lindert
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Matthew Elmore
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Philip L. Vines
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
| | - Sharron Crane
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA;
| | - Ivelisse Irizarry
- School of Health and Sciences, Universidad del Sagrado Corazón, San Juan 00914, Puerto Rico;
| | - Kurt P. Kowalski
- US Geological Survey Great Lakes Science Center, Ann Arbor, MI 48105, USA;
| | - David Johnston-Monje
- Max Planck Tandem Group in Plant Microbial Ecology, Universidad del Valle, Cali 760043, Colombia;
| | - James F. White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (Q.Z.); (X.C.); (K.K.); (L.P.); (P.C.); (R.S.); (F.V.); (S.L.); (M.E.); (P.L.V.)
- Correspondence: (A.M.); (J.F.W.); Tel.: +848-932-6286 (J.F.W.)
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Sahu KP, Kumar A, Sakthivel K, Reddy B, Kumar M, Patel A, Sheoran N, Gopalakrishnan S, Prakash G, Rathour R, Gautam RK. Deciphering core phyllomicrobiome assemblage on rice genotypes grown in contrasting agroclimatic zones: implications for phyllomicrobiome engineering against blast disease. ENVIRONMENTAL MICROBIOME 2022; 17:28. [PMID: 35619157 PMCID: PMC9134649 DOI: 10.1186/s40793-022-00421-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 05/09/2022] [Indexed: 05/16/2023]
Abstract
BACKGROUND With its adapted microbial diversity, the phyllosphere contributes microbial metagenome to the plant holobiont and modulates a host of ecological functions. Phyllosphere microbiome (hereafter termed phyllomicrobiome) structure and the consequent ecological functions are vulnerable to a host of biotic (Genotypes) and abiotic factors (Environment) which is further compounded by agronomic transactions. However, the ecological forces driving the phyllomicrobiome assemblage and functions are among the most understudied aspects of plant biology. Despite the reports on the occurrence of diverse prokaryotic phyla such as Proteobacteria, Firmicutes, Bacteroides, and Actinobacteria in phyllosphere habitat, the functional characterization leading to their utilization for agricultural sustainability is not yet explored. Currently, the metabarcoding by Next-Generation-Sequencing (mNGS) technique is a widely practised strategy for microbiome investigations. However, the validation of mNGS annotations by culturomics methods is not integrated with the microbiome exploration program. In the present study, we combined the mNGS with culturomics to decipher the core functional phyllomicrobiome of rice genotypes varying for blast disease resistance planted in two agroclimatic zones in India. There is a growing consensus among the various stakeholder of rice farming for an ecofriendly method of disease management. Here, we proposed phyllomicrobiome assisted rice blast management as a novel strategy for rice farming in the future. RESULTS The tropical "Island Zone" displayed marginally more bacterial diversity than that of the temperate 'Mountain Zone' on the phyllosphere. Principal coordinate analysis indicated converging phyllomicrobiome profiles on rice genotypes sharing the same agroclimatic zone. Interestingly, the rice genotype grown in the contrasting zones displayed divergent phyllomicrobiomes suggestive of the role of environment on phyllomicrobiome assembly. The predominance of phyla such as Proteobacteria, Actinobacteria, and Firmicutes was observed in the phyllosphere irrespective of the genotypes and climatic zones. The core-microbiome analysis revealed an association of Acidovorax, Arthrobacter, Bacillus, Clavibacter, Clostridium, Cronobacter, Curtobacterium, Deinococcus, Erwinia, Exiguobacterium, Hymenobacter, Kineococcus, Klebsiella, Methylobacterium, Methylocella, Microbacterium, Nocardioides, Pantoea, Pedobacter, Pseudomonas, Salmonella, Serratia, Sphingomonas and Streptomyces on phyllosphere. The linear discriminant analysis (LDA) effect size (LEfSe) method revealed distinct bacterial genera in blast-resistant and susceptible genotypes, as well as mountain and island climate zones. SparCC based network analysis of phyllomicrobiome showed complex intra-microbial cooperative or competitive interactions on the rice genotypes. The culturomic validation of mNGS data confirmed the occurrence of Acinetobacter, Aureimonas, Curtobacterium, Enterobacter, Exiguobacterium, Microbacterium, Pantoea, Pseudomonas, and Sphingomonas in the phyllosphere. Strikingly, the contrasting agroclimatic zones showed genetically identical bacterial isolates suggestive of vertical microbiome transmission. The core-phyllobacterial communities showed secreted and volatile compound mediated antifungal activity on M. oryzae. Upon phyllobacterization (a term coined for spraying bacterial cells on the phyllosphere), Acinetobacter, Aureimonas, Pantoea, and Pseudomonas conferred immunocompetence against blast disease. Transcriptional analysis revealed activation of defense genes such as OsPR1.1, OsNPR1, OsPDF2.2, OsFMO, OsPAD4, OsCEBiP, and OsCERK1 in phyllobacterized rice seedlings. CONCLUSIONS PCoA indicated the key role of agro-climatic zones to drive phyllomicrobiome assembly on the rice genotypes. The mNGS and culturomic methods showed Acinetobacter, Aureimonas, Curtobacterium, Enterobacter, Exiguobacterium, Microbacterium, Pantoea, Pseudomonas, and Sphingomonas as core phyllomicrobiome of rice. Genetically identical Pantoea intercepted on the phyllosphere from the well-separated agroclimatic zones is suggestive of vertical transmission of phyllomicrobiome. The phyllobacterization showed potential for blast disease suppression by direct antibiosis and defense elicitation. Identification of functional core-bacterial communities on the phyllosphere and their co-occurrence dynamics presents an opportunity to devise novel strategies for rice blast management through phyllomicrobiome reengineering in the future.
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Affiliation(s)
- Kuleshwar Prasad Sahu
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | - A Kumar
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India.
| | - K Sakthivel
- Division of Field Crop Improvement and Protection, ICAR-Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands, 744101, India
| | - Bhaskar Reddy
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Mukesh Kumar
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Asharani Patel
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Neelam Sheoran
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | | | - Ganesan Prakash
- Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Rajeev Rathour
- Department of Agricultural Biotechnology, CSK Himachal Pradesh Agricultural University, Palampur, Himachal Pradesh, 176062, India
| | - R K Gautam
- Division of Field Crop Improvement and Protection, ICAR-Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands, 744101, India
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27
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Dynamic character displacement among a pair of bacterial phyllosphere commensals in situ. Nat Commun 2022; 13:2836. [PMID: 35595740 PMCID: PMC9123166 DOI: 10.1038/s41467-022-30469-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 05/03/2022] [Indexed: 11/09/2022] Open
Abstract
Differences between species promote stable coexistence in a resource-limited environment. These differences can result from interspecies competition leading to character shifts, a process referred to as character displacement. While character displacement is often interpreted as a consequence of genetically fixed trait differences between species, it can also be mediated by phenotypic plasticity in response to the presence of another species. Here, we test whether phenotypic plasticity leads to a shift in proteome allocation during co-occurrence of two bacterial species from the abundant, leaf-colonizing families Sphingomonadaceae and Rhizobiaceae in their natural habitat. Upon mono-colonizing of the phyllosphere, both species exhibit specific and shared protein functions indicating a niche overlap. During co-colonization, quantitative differences in the protein repertoire of both bacterial populations occur as a result of bacterial coexistence in planta. Specifically, the Sphingomonas strain produces enzymes for the metabolization of xylan, while the Rhizobium strain reprograms its metabolism to beta-oxidation of fatty acids fueled via the glyoxylate cycle and adapts its biotin acquisition. We demonstrate the conditional relevance of cross-species facilitation by mutagenesis leading to loss of fitness in competition in planta. Our results show that dynamic character displacement and niche facilitation mediated by phenotypic plasticity can contribute to species coexistence. In this study, the concept of dynamic character displacement among interacting bacterial species from leaf-colonizing families was empirically tested using a proteomics approach. A phenotypic shift towards the utilization of alternative carbon sources was observed during coexistence, thereby minimizing niche overlap.
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28
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Choudhury AR, Roy SK, Trivedi P, Choi J, Cho K, Yun SH, Walitang DI, Park JH, Kim K, Sa T. Label-free proteomics approach reveals candidate proteins in rice (Oryza sativa L.) important for ACC deaminase producing bacteria-mediated tolerance against salt stress. Environ Microbiol 2022; 24:3612-3624. [PMID: 35191581 DOI: 10.1111/1462-2920.15937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 11/30/2022]
Abstract
The omics-based studies are important for identifying characteristic proteins in plants to elucidate the mechanism of ACC deaminase producing bacteria-mediated salt tolerance. This study evaluates the changes in the proteome of rice inoculated with ACC deaminase producing bacteria under salt stress conditions. Salt stress resulted in a significant decrease in photosynthetic pigments, whereas inoculation of Methylobacterium oryzae CBMB20 had significantly increased pigment contents under normal and salt stress conditions. A total of 76, 51 and 33 differentially abundant proteins (DAPs) were identified in non-inoculated salt stressed plants, bacteria inoculated plants under normal and salt stress conditions, respectively. The abundances of proteins responsible for ethylene emission and programmed cell death were increased, and that of photosynthesis-related proteins were decreased in non-inoculated plants under salt stress. Whereas, bacteria-inoculated plants had shown higher abundance of antioxidant proteins, RuBisCo and ribosomal proteins that are important for enhancing stress tolerance and improving plant physiological traits. Collectively, salt stress might affect plant physiological traits by impairing photosynthetic machinery and accelerating apoptosis leading to a decline in biomass. However, inoculation of plants with bacteria can assist in enhancing photosynthetic activity, antioxidant activities and ethylene regulation related proteins for attenuating salt induced apoptosis and sustaining growth and development. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Aritra Roy Choudhury
- Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Republic of Korea.,Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, Republic of Korea
| | - Swapan Kumar Roy
- College of Agricultural Sciences, IUBAT-International University of Business Agriculture and Technology, Dhaka, Bangladesh
| | - Pankaj Trivedi
- Microbiome Network and Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
| | - Jeongyun Choi
- Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Republic of Korea.,Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
| | - Kun Cho
- Bio-chemical Analysis Team, Center for Research Equipment, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Sung Ho Yun
- Bio-chemical Analysis Team, Center for Research Equipment, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Denver I Walitang
- Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Republic of Korea.,College of Agriculture, Fisheries and Forestry, Romblon State University, Philippines
| | - Jung-Ho Park
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, Republic of Korea.,Department of Bioprocess Engineering, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Kiyoon Kim
- National Forest Seed Variety Center, Chungju, Republic of Korea
| | - Tongmin Sa
- Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Republic of Korea.,The Korean Academy of Science and Technology, Seongnam, Republic of Korea
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Abstract
A key challenge in microbiome science is the scale mismatch problem, which arises when the scale at which microbial communities are sampled, interrogated, and averaged is different from the scale at which individual microorganisms within those communities interact with each other and with their environment. Profiling the microbial communities in a teaspoon of soil, from a scoop of fecal matter, or along a plant leaf surface represents a scale mismatch of multiple orders of magnitude, which may limit our ability to interpret or predict species interactions and community assembly within such samples. In this Perspective, we explore how economists, who are historically and topically split along the lines of micro- and macroeconomics, deal with the scale mismatch problem, and how taking clues from (micro)economists could benefit the field of microbiomics.
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30
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Sahu KP, Patel A, Kumar M, Sheoran N, Mehta S, Reddy B, Eke P, Prabhakaran N, Kumar A. Integrated Metabarcoding and Culturomic-Based Microbiome Profiling of Rice Phyllosphere Reveal Diverse and Functional Bacterial Communities for Blast Disease Suppression. Front Microbiol 2021; 12:780458. [PMID: 34917058 PMCID: PMC8669949 DOI: 10.3389/fmicb.2021.780458] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 10/20/2021] [Indexed: 11/13/2022] Open
Abstract
Phyllosphere-the harsh foliar plant part exposed to vagaries of environmental and climatic variables is a unique habitat for microbial communities. In the present work, we profiled the phyllosphere microbiome of the rice plants using 16S rRNA gene amplicon sequencing (hereafter termed metabarcoding) and the conventional microbiological methods (culturomics) to decipher the microbiome assemblage, composition, and their functions such as antibiosis and defense induction against rice blast disease. The blast susceptible rice genotype (PRR78) harbored far more diverse bacterial species (294 species) than the resistant genotype (Pusa1602) that showed 193 species. Our metabarcoding of bacterial communities in phyllomicrobiome revealed the predominance of the phylum, Proteobacteria, and its members Pantoea, Enterobacter, Pseudomonas, and Erwinia on the phyllosphere of both rice genotypes. The microbiological culturomic validation of metabarcoding-taxonomic annotation further confirmed the prevalence of 31 bacterial isolates representing 11 genera and 16 species with the maximum abundance of Pantoea. The phyllomicrobiome-associated bacterial members displayed antifungal activity on rice blast fungus, Magnaporthe oryzae, by volatile and non-volatile metabolites. Upon phyllobacterization of rice cultivar PB1, the bacterial species such as Enterobacter sacchari, Microbacterium testaceum, Pantoea ananatis, Pantoea dispersa, Pantoea vagans, Pseudomonas oryzihabitans, Rhizobium sp., and Sphingomonas sp. elicited a defense response and contributed to the suppression of blast disease. qRT-PCR-based gene expression analysis indicated over expression of defense-associated genes such as OsCEBiP, OsCERK1, and phytohormone-associated genes such as OsPAD4, OsEDS1, OsPR1.1, OsNPR1, OsPDF2.2, and OsFMO in phyllobacterized rice seedlings. The phyllosphere bacterial species showing blast suppressive activity on rice were found non-plant pathogenic in tobacco infiltration assay. Our comparative microbiome interrogation of the rice phyllosphere culminated in the isolation and identification of agriculturally significant bacterial communities for blast disease management in rice farming through phyllomicrobiome engineering in the future.
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Affiliation(s)
- Kuleshwar Prasad Sahu
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Asharani Patel
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Mukesh Kumar
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Neelam Sheoran
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Sahil Mehta
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Bhaskar Reddy
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Pierre Eke
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | | | - Aundy Kumar
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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31
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Xiong BJ, Dusny C, Wang L, Appel J, Lindstaedt K, Schlosser D, Harms H, Wick LY. Illuminate the hidden: in vivo mapping of microscale pH in the mycosphere using a novel whole-cell biosensor. ISME COMMUNICATIONS 2021; 1:75. [PMID: 36765263 PMCID: PMC9723660 DOI: 10.1038/s43705-021-00075-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 01/07/2023]
Abstract
The pH of an environment is both a driver and the result of diversity and functioning of microbial habitats such as the area affected by fungal hyphae (mycosphere). Here we used a novel pH-sensitive bioreporter, Synechocystis sp. PCC6803_peripHlu, and ratiometric fluorescence microscopy, to spatially and temporally resolve the mycosphere pH at the micrometre scale. Hyphae of the basidiomycete Coprionopsis cinerea were allowed to overgrow immobilised and homogeneously embedded pH bioreporters in an agarose microcosm. Signals of >700 individual cells in an area of 0.4 × 0.8 mm were observed over time and used to create highly resolved (3 × 3 µm) pH maps using geostatistical approaches. C. cinerea changed the pH of the agarose from 6.9 to ca. 5.0 after 48 h with hyphal tips modifying pH in their vicinity up to 1.8 mm. pH mapping revealed distinct microscale spatial variability and temporally stable gradients between pH 4.4 and 5.8 over distances of ≈20 µm. This is the first in vivo mapping of a mycosphere pH landscape at the microscale. It underpins the previously hypothesised establishment of pH gradients serving to create spatially distinct mycosphere reaction zones.
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Affiliation(s)
- Bi-Jing Xiong
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany
| | - Christian Dusny
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany
| | - Lin Wang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jens Appel
- Department of Biology, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 5, 24118, Kiel, Germany
| | - Kristin Lindstaedt
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany
| | - Dietmar Schlosser
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany
| | - Lukas Y Wick
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany.
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Santoyo G. How plants recruit their microbiome? New insights into beneficial interactions. J Adv Res 2021; 40:45-58. [PMID: 36100333 PMCID: PMC9481936 DOI: 10.1016/j.jare.2021.11.020] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/25/2021] [Accepted: 11/30/2021] [Indexed: 01/07/2023] Open
Abstract
Plant-microbiome interaction occurs at the rhizosphere, endosphere, and phyllosphere. Root exudates can favor the recruitment of a beneficial microbiome in the rhizosphere. Plant topology and phytochemistry influence the recruitment of the phyllosphere microbiome. Diverse plant strategies selectively recruit beneficial microbiomes. Multiple plant mechanisms displace potential pathogens from the rhizosphere. The beneficial microbiome helps plants to recruit other beneficial microbiota.
Background Research on beneficial mechanisms by plant-associated microbiomes, such as plant growth stimulation and protection from plant pathogens, has gained considerable attention over the past decades; however, the mechanisms used by plants to recruit their microbiome is largely unknown. Aim of Review Here, we review the latest studies that have begun to reveal plant strategies in selectively recruiting beneficial microbiomes, and how they manage to exclude potential pathogens. Key Scientific concepts of Review: We examine how plants attract beneficial microbiota from the main areas of interaction, such as the rhizosphere, endosphere, and phyllosphere, and demonstrate that such process occurs by producing root exudates, and recognizing molecules produced by the beneficial microbiota or distinguishing pathogens using specific receptors, or by triggering signals that support plant-microbiome homeostasis. Second, we analyzed the main environmental or biotic factors that modulate the structure and successional dynamics of microbial communities. Finally, we review how the associated microbiome is capable of engaging with other synergistic microbes, hence providing an additional element of selection. Collectively, this study reveals the importance of understanding the complex network of plant interactions, which will improve the understanding of bioinoculant application in agriculture, based on a microbiome that interacts efficiently with plant organs under different environmental conditions.
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Affiliation(s)
- Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030 Morelia, Mexico.
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Alsanius BW, Vaas L, Gharaie S, Karlsson ME, Rosberg AK, Wohanka W, Khalil S, Windstam S. Dining in Blue Light Impairs the Appetite of Some Leaf Epiphytes. Front Microbiol 2021; 12:725021. [PMID: 34733247 PMCID: PMC8558677 DOI: 10.3389/fmicb.2021.725021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/10/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The phyllosphere is subjected to fluctuating abiotic conditions. This study examined the phenotypic plasticity (PP) of four selected non-phototrophic phyllosphere bacteria [control strain: Pseudomonas sp. DR 5-09; Pseudomonas agarici, Bacillus thuringiensis serovar israeliensis (Bti), and Streptomyces griseoviridis (SG)] regarding their respiration patterns and surfactant activity as affected by light spectrum and nutrient supply. Methods: The PP of the strains was examined under four light regimes [darkness (control); monochromatic light-emitting diodes (LED) at 460 nm (blue) and 660 nm (red); continuously polychromatic white LEDs], in the presence of 379 substrates and conditions. Results: Light treatment affected the studied bacterial strains regarding substrate utilization (Pseudomonas strains > SG > Bti). Blue LEDs provoked the most pronounced impact on the phenotypic reaction norms of the Pseudomonas strains and Bti. The two Gram-positive strains Bti and SG, respectively, revealed inconsistent biosurfactant formation in all cases. Biosurfactant formation by both Pseudomonas strains was supported by most substrates incubated in darkness, and blue LED exposure altered the surface activity profoundly. Blue and white LEDs enhanced biofilm formation in PA in highly utilized C-sources. Putative blue light receptor proteins were found in both Pseudomonas strains, showing 91% similarity with the sequence from NCBI accession number WP_064119393. Conclusion: Light quality–nutrient interactions affect biosurfactant activity and biofilm formation of some non-phototrophic phyllosphere bacteria and are, thus, crucial for dynamics of the phyllosphere microbiome.
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Affiliation(s)
- Beatrix W Alsanius
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
| | - Lea Vaas
- Fraunhofer IME, Computational Biology, Screening Port, Hamburg, Germany
| | - Samareh Gharaie
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
| | - Maria E Karlsson
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
| | - Anna Karin Rosberg
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
| | - Walter Wohanka
- Department of Phytomedicine, Geisenheim University, Geisenheim, Germany
| | - Sammar Khalil
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
| | - Sofia Windstam
- Microbial Horticulture Unit, Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Lomma, Sweden
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Truong H, Garmyn D, Gal L, Fournier C, Sevellec Y, Jeandroz S, Piveteau P. Plants as a realized niche for Listeria monocytogenes. Microbiologyopen 2021; 10:e1255. [PMID: 34964288 PMCID: PMC8710918 DOI: 10.1002/mbo3.1255] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/09/2021] [Accepted: 11/18/2021] [Indexed: 12/27/2022] Open
Abstract
Listeria monocytogenes is a human pathogen. It is the causative agent of listeriosis, the leading cause of bacterial-linked foodborne mortality in Europe and elsewhere. Outbreaks of listeriosis have been associated with the consumption of fresh produce including vegetables and fruits. In this review we summarize current data providing direct or indirect evidence that plants can serve as habitat for L. monocytogenes, enabling this human pathogen to survive and grow. The current knowledge of the mechanisms involved in the interaction of this bacterium with plants is addressed, and whether this foodborne pathogen elicits an immune response in plants is discussed.
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Affiliation(s)
- Hoai‐Nam Truong
- Agroécologie, AgroSup Dijon, CNRS, INRAEUniversity Bourgogne Franche‐ComtéDijonFrance
| | - Dominique Garmyn
- Agroécologie, AgroSup Dijon, CNRS, INRAEUniversity Bourgogne Franche‐ComtéDijonFrance
| | - Laurent Gal
- Agroécologie, AgroSup Dijon, CNRS, INRAEUniversity Bourgogne Franche‐ComtéDijonFrance
| | - Carine Fournier
- Agroécologie, AgroSup Dijon, CNRS, INRAEUniversity Bourgogne Franche‐ComtéDijonFrance
| | - Yann Sevellec
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Laboratory for Food Safety, Salmonella and Listeria UnitParis‐Est UniversityMaisons‐AlfortCedexFrance
| | - Sylvain Jeandroz
- Agroécologie, AgroSup Dijon, CNRS, INRAEUniversity Bourgogne Franche‐ComtéDijonFrance
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de Medeiros Azevedo T, Aburjaile FF, Ferreira-Neto JRC, Pandolfi V, Benko-Iseppon AM. The endophytome (plant-associated microbiome): methodological approaches, biological aspects, and biotech applications. World J Microbiol Biotechnol 2021; 37:206. [PMID: 34708327 DOI: 10.1007/s11274-021-03168-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/05/2021] [Indexed: 11/25/2022]
Abstract
Similar to other organisms, plants establish interactions with a variety of microorganisms in their natural environment. The plant microbiome occupies the host plant's tissues, either internally or on its surfaces, showing interactions that can assist in its growth, development, and adaptation to face environmental stresses. The advance of metagenomics and metatranscriptomics approaches has strongly driven the study and recognition of plant microbiome impacts. Research in this regard provides comprehensive information about the taxonomic and functional aspects of microbial plant communities, contributing to a better understanding of their dynamics. Evidence of the plant microbiome's functional potential has boosted its exploitation to develop more ecological and sustainable agricultural practices that impact human health. Although microbial inoculants' development and use are promising to revolutionize crop production, interdisciplinary studies are needed to identify new candidates and promote effective practical applications. On the other hand, there are challenges in understanding and analyzing complex data generated within a plant microbiome project's scope. This review presents aspects about the complex structuring and assembly of the microbiome in the host plant's tissues, metagenomics, and metatranscriptomics approaches for its understanding, covering descriptions of recent studies concerning metagenomics to characterize the microbiome of non-model plants under different aspects. Studies involving bio-inoculants, isolated from plant microbial communities, capable of assisting in crops' productivity, are also reviewed.
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Affiliation(s)
- Thamara de Medeiros Azevedo
- Departamento de Genética, Centro de Biociências, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife, PE, CEP: 50670-901, Brazil
| | - Flávia Figueira Aburjaile
- Departamento de Genética, Centro de Biociências, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife, PE, CEP: 50670-901, Brazil
| | - José Ribamar Costa Ferreira-Neto
- Departamento de Genética, Centro de Biociências, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife, PE, CEP: 50670-901, Brazil
| | - Valesca Pandolfi
- Departamento de Genética, Centro de Biociências, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife, PE, CEP: 50670-901, Brazil
| | - Ana Maria Benko-Iseppon
- Departamento de Genética, Centro de Biociências, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife, PE, CEP: 50670-901, Brazil.
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Yan K, Han W, Zhu Q, Li C, Dong Z, Wang Y. Leaf surface microtopography shaping the bacterial community in the phyllosphere: evidence from 11 tree species. Microbiol Res 2021; 254:126897. [PMID: 34710835 DOI: 10.1016/j.micres.2021.126897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/27/2021] [Accepted: 10/13/2021] [Indexed: 10/20/2022]
Abstract
Phyllosphere bacteria are an important component of environmental microbial communities and are closely related to plant health and ecosystem stability. However, the relationships between the inhabitation and assembly of phyllosphere bacteria and leaf microtopography are still obscure. In this study, the phyllosphere bacterial communities and leaf microtopographic features (vein density, stomatal length, and density) of eleven tree species were fully examined. Both the absolute abundance and diversity of phyllosphere bacterial communities were significantly different among the tree species, and leaf vein density dominated the variation. TITAN analysis showed that leaf vein density also played more important roles in regulating the relative abundance of bacteria than stomatal features, and 6 phyla and 62 genera of phyllosphere bacteria showed significant positive responses to leaf vein density. Moreover, LEfSe analysis showed that the leaves with higher vein density had more bacterial biomarkers. Leaf vein density also changed the co-occurrence pattern of phyllosphere bacteria, and the co-occurrence network demonstrated more negative correlations and more nodes on the leaves with larger leaf vein density, indicating that higher densities of leaf veins improved the stability of the phyllosphere bacterial community. Phylogenetic analysis showed that deterministic processes (especially homogeneous selection) dominated the assembly process of phyllosphere bacterial communities. The leaf vein density increased the degree of bacterial clustering at the phylogenetic level. Therefore, the inhabitation and assembly of the phyllosphere bacterial community are related to leaf microtopography, which provides deeper insight into the interaction between plants and bacteria.
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Affiliation(s)
- Kun Yan
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China
| | - Wenhao Han
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China
| | - Qiliang Zhu
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China
| | - Chuanrong Li
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China
| | - Zhi Dong
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China
| | - Yanping Wang
- Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, 271018, PR China.
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Sun X, Zheng Y, Xu G, Guo Q, Tan J, Ding G. Fungal diversity within the phyllosphere of Pinus massoniana and the possible involvement of phyllospheric fungi in litter decomposition. Fungal Biol 2021; 125:785-795. [PMID: 34537174 DOI: 10.1016/j.funbio.2021.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/29/2021] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
Fungi play key roles in forest ecosystems and help to shape the forest's diverse functions. However, little is known about the diversity of phyllospheric fungi or their possible relationships with fungal communities residing in different micro-environments of Pinus massoniana forests. We investigated seven different sample types: mature needles (NM), dead needles (ND), needles falling as litter (L), fermenting needles (F), humus (H), top soil (0-20 cm) (TS), and secondary soil (20-40 cm) (SS). These seven fungal communities were examined and compared with ITS amplicons using a high-throughput sequencing technique. A total of 1213 fungal operational taxonomic units (OTUs) were obtained at a 97% sequence similarity level. Distinct fungal communities were associated with different sample types. A greater number of OTUs were present in both NM and F samples than those shared by both NM and TS samples, indicating that phyllospheric fungi may play crucial roles in litter decomposition. Sixty OTUs (the core microbiome) were found in all sample types, and they may probably play different ecological roles in different sample types. These findings extend our knowledge of the fungal diversity of the phyllosphere and its possible interactions with fungal communities found in distinct forest micro-habitats.
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Affiliation(s)
- Xueguang Sun
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang, Guizhou, 550025, China; College of Forestry, Guizhou University, Guiyang, 550025, China.
| | - Yang Zheng
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang, Guizhou, 550025, China; College of Forestry, Guizhou University, Guiyang, 550025, China
| | - Gang Xu
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang, Guizhou, 550025, China; College of Forestry, Guizhou University, Guiyang, 550025, China
| | - Qiqiang Guo
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang, Guizhou, 550025, China; College of Forestry, Guizhou University, Guiyang, 550025, China
| | - Jianhui Tan
- Guangxi Zhuang Autonomous Region Forestry Research Institute, Nanning, Guangxi, 530002, China
| | - Guijie Ding
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang, Guizhou, 550025, China; College of Forestry, Guizhou University, Guiyang, 550025, China
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Palmer JL, Hilton S, Picot E, Bending GD, Schäfer H. Tree phyllospheres are a habitat for diverse populations of CO-oxidizing bacteria. Environ Microbiol 2021; 23:6309-6327. [PMID: 34523801 DOI: 10.1111/1462-2920.15770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/21/2021] [Accepted: 09/08/2021] [Indexed: 11/28/2022]
Abstract
Carbon monoxide (CO) is both a ubiquitous atmospheric trace gas and an air pollutant. While aerobic CO-degrading microorganisms in soils and oceans are estimated to remove ~370 Tg of CO per year, the presence of CO-degrading microorganisms in above-ground habitats, such as the phyllosphere, and their potential role in CO cycling remains unknown. CO-degradation by leaf washes of two common British trees, Ilex aquifolium and Crataegus monogyna, demonstrated CO uptake in all samples investigated. Based on the analyses of taxonomic and functional genes, diverse communities of candidate CO-oxidizing taxa were identified, including members of Rhizobiales and Burkholderiales which were abundant in the phyllosphere at the time of sampling. Based on predicted genomes of phyllosphere community members, an estimated 21% of phyllosphere bacteria contained CoxL, the large subunit of CO-dehydrogenase. In support of this, data mining of publicly available phyllosphere metagenomes for genes encoding CO-dehydrogenase subunits demonstrated that, on average, 25% of phyllosphere bacteria contained CO-dehydrogenase gene homologues. A CO-oxidizing Phyllobacteriaceae strain was also isolated from phyllosphere samples which contains genes encoding both CO-dehydrogenase as well as a ribulose-1,5-bisphosphate carboxylase-oxygenase. These results suggest that the phyllosphere supports diverse and potentially abundant CO-oxidizing bacteria, which are a potential sink for atmospheric CO.
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Affiliation(s)
- Jess L Palmer
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Sally Hilton
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Emma Picot
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Gary D Bending
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Hendrik Schäfer
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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Lajoie G, Kembel SW. Plant-bacteria associations are phylogenetically structured in the phyllosphere. Mol Ecol 2021; 30:5572-5587. [PMID: 34411359 DOI: 10.1111/mec.16131] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/24/2022]
Abstract
Determining whether and how global change will lead to novel interactions between hosts and microbes is an important issue in ecology and evolution. Understanding the contribution of host and microbial ecologies and evolutionary histories in driving their contemporary associations is an important step towards addressing this challenge and predicting the fitness consequences of novel associations. Using shotgun metagenomic and amplicon sequencing of bacterial communities from the leaf surfaces (phyllosphere) of trees, we investigated how phylogenetic relatedness among hosts and among their associated bacteria influences the distribution of bacteria among hosts. We also evaluated whether the functional traits of trees and bacteria explained these associations across multiple host species. We show that phylogenetically similar hosts tended to associate with the same bacteria and that phylogenetically similar bacteria tended to associate with the same host species. Phylogenetic interactions between tree and bacterial taxa also explained variation in their associations. The effect of host and symbiont evolutionary histories on bacterial distribution across hosts were observed across phylogenetic scales, but prominently explained variation among higher taxonomic categories of hosts and symbionts. These results suggest that ecological variation arising early in the plant and bacterial phylogenies have been particularly important for driving their contemporary associations. Variation in bacterial functional genes associated with the biosynthesis of aromatic amino acids and compounds and with cell motility were notably important in explaining bacterial community turnover among gymnosperm and angiosperm hosts. Overall, our results suggest an influence of host and bacterial traits and evolutionary histories in driving their contemporary associations.
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Affiliation(s)
- Geneviève Lajoie
- Département des Sciences Biologiques, Université du Québec à Montréal, 141 Avenue du Président-Kennedy, Montréal, QC, H2X 1Y4, Canada
| | - Steven W Kembel
- Département des Sciences Biologiques, Université du Québec à Montréal, 141 Avenue du Président-Kennedy, Montréal, QC, H2X 1Y4, Canada
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Processing of leafy vegetables matters: Damage and microbial community structure from field to bag. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107894] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Gao B, Sun Q. Programming gene expression in multicellular organisms for physiology modulation through engineered bacteria. Nat Commun 2021; 12:2689. [PMID: 33976154 PMCID: PMC8113242 DOI: 10.1038/s41467-021-22894-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 03/29/2021] [Indexed: 02/07/2023] Open
Abstract
A central goal of synthetic biology is to predictably and efficiently reprogram living systems to perform computations and carry out specific biological tasks. Although there have been many advances in the bio-computational design of living systems, these advances have mainly been applied to microorganisms or cell lines; programming animal physiology remains challenging for synthetic biology because of the system complexity. Here, we present a bacteria-animal symbiont system in which engineered bacteria recognize external signals and modulate animal gene expression, twitching phenotype, and fat metabolism through RNA interference toward gfp, sbp-1, and unc-22 gene in C. elegans. By using genetic circuits in bacteria to control these RNA expressions, we are able to program the physiology of the model animal Caenorhabditis elegans with logic gates. We anticipate that engineered bacteria can be used more extensively to program animal physiology for agricultural, therapeutic, and basic science applications.
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Affiliation(s)
- Baizhen Gao
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Qing Sun
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
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Yan ZZ, Chen QL, Li CY, Thi Nguyen BA, Zhu YG, He JZ, Hu HW. Biotic and abiotic factors distinctly drive contrasting biogeographic patterns between phyllosphere and soil resistomes in natural ecosystems. ISME COMMUNICATIONS 2021; 1:13. [PMID: 36721011 PMCID: PMC9645249 DOI: 10.1038/s43705-021-00012-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/02/2021] [Accepted: 03/11/2021] [Indexed: 02/03/2023]
Abstract
The phyllosphere and soil are two of the most important reservoirs of antibiotic resistance genes (ARGs) in terrestrial ecosystems. However, comparative studies on the biogeographic patterns of ARGs in these two habitats are lacking. Based on the construction of ARG abundance atlas across a > 4,000 km transect in eastern and northern Australia, we found contrasting biogeographic patterns of the phyllosphere and soil resistomes, which showed their distinct responses to the biotic and abiotic stresses. The similarity of ARG compositions in soil, but not in the phyllosphere, exhibited significant distance-decay patterns. ARG abundance in the phyllosphere was mainly correlated with the compositions of co-occurring bacterial, fungal and protistan communities, indicating that biotic stresses were the main drivers shaping the phyllosphere resistome. Soil ARG abundance was mainly associated with abiotic factors including mean annual temperature and precipitation as well as soil total carbon and nitrogen. Our findings demonstrated the distinct roles of biotic and abiotic factors in shaping resistomes in different environmental habitats. These findings constitute a major advance in our understanding of the current environmental resistomes and contribute to better predictions of the evolution of environmental ARGs by highlighting the importance of habitat difference in shaping environmental resistomes.
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Affiliation(s)
- Zhen-Zhen Yan
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Qing-Lin Chen
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
| | - Chao-Yu Li
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Bao-Anh Thi Nguyen
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Ji-Zheng He
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hang-Wei Hu
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
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Liu L, Lu L, Li H, Meng Z, Dong T, Peng C, Xu X. Divergence of Phyllosphere Microbial Communities Between Females and Males of the Dioecious Populus cathayana. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:351-361. [PMID: 33290085 DOI: 10.1094/mpmi-07-20-0178-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Females and males of dioecious plants have evolved sex-specific characteristics in terms of their morphological and physiological properties. However, the differentiation of phyllosphere microbiota in dioecious plants remains largely unexplored. Here, the diversity and composition of female and male Populus cathayana phyllosphere bacterial and fungal communities were investigated using 16S rRNA/ITS1 gene-based MiSeq sequencing. The divergences of bacterial and fungal community compositions occurred between females and males. Both females and males had their unique phyllosphere bacterial and fungal microbiota, such as bacterial Gemmata spp. (5.41%) and fungal Pringsheimia spp. (0.03%) in females and bacterial Chitinophaga spp. (0.009%) and fungal Phaeococcomyces spp. (0.02%) in males. Significant differences in the relative abundance of phyla Proteobacteria and Planctomycetes bacteria and phyla Ascomycota and Basidiomycota fungi (P < 0.05) were also found between females and males. Some bacterial species of genera Spirosoma and Amnibacterium and fungal genera Venturia, Suillus, and Elmerina spp. were significantly enriched in males (P < 0.05). In contrast, levels of fungal genera Phoma and Aureobasidium spp. were significantly higher in females than in males (P < 0.05). The mineral, inorganic, and organic nutrients content contributed differently to the divergence of female and male phyllosphere microbial communities, with 87.08 and 45.17% of the variations being explained for bacterial and fungal communities, respectively. These results highlight the sexual discrimination of phyllosphere microbes on the dioecious plants and provide hints on the potential host-associated species in phyllosphere environments.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Liling Liu
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
- Institute of Ecology, China West Normal University, Nanchong 637009, China
| | - Lu Lu
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
- College of Environmental Science and Engineering, China West Normal University, Nanchong 637009, China
| | - Huilin Li
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
| | - Zhensi Meng
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
| | - Tingfa Dong
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
| | - Chao Peng
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, China
| | - Xiao Xu
- Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Sciences, China West Normal University, Nanchong 637002, China
- Institute of Ecology, China West Normal University, Nanchong 637009, China
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Leaf-FISH: In Situ Hybridization Method for Visualizing Bacterial Taxa on Plant Surfaces. Methods Mol Biol 2021. [PMID: 33576986 DOI: 10.1007/978-1-0716-1115-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
High-resolution, spatial characterization of microbial communities is critical for the accurate understanding of microbe-microbe and microbe-plant interactions in leaf surfaces (phyllosphere). However, leaves are specially challenging surfaces for imaging methods due to their high autofluorescence. In this chapter we describe the Leaf-FISH method. Leaf-FISH is a fluorescence in situ hybridization (FISH) method specially adapted to the requirements of plant tissues. Leaf-FISH uses a combination of leaf pretreatments coupled with spectral imaging confocal microscopy and image post-processing to visualize bacterial taxa on a structural-informed context recreated from the residual background autofluorescence of the tissues. Leaf-FISH is suitable for simultaneous identification of multiple bacterial taxa using multiple taxon-specific fluorescently labeled oligonucleotide probes (combinatorial labeling).
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Abstract
Production of the biosurfactant syringafactin by the plant pathogen Pseudomonas syringae B728a is a surface contact-dependent trait. Expression of syfA, as measured using a gfp reporter gene fusion was low in planktonic cells in liquid cultures but over 4-fold higher in cells immobilized on surfaces as varied as glass, plastic, paper, parafilm, agar, membrane filters, and leaves. Induction of syfA as measured by GFP fluorescence was rapid, occurring within two hours after immobilization of cells on surfaces. Comparison of the global transcriptome by RNA sequencing of planktonic cells in a nutrient medium with that of cells immobilized for 2 hours on filters placed on this solidified medium revealed that, in addition to syfA, 3156 other genes were differentially expressed. Genes repressed in immobilized cells included those involved in quaternary ammonium compound (QAC) metabolism and transport, compatible solute production, carbohydrate metabolism and transport, organic acid metabolism and transport, phytotoxin synthesis and transport, amino acid metabolism and transport, and secondary metabolism. Genes induced in immobilized cells included syfA plus those involved in translation, siderophore synthesis and transport, nucleotide metabolism and transport, flagellar synthesis and motility, lipopolysaccharide (LPS) synthesis and transport, energy generation, transcription, chemosensing and chemotaxis, replication and DNA repair, iron-sulfur proteins, peptidoglycan/cell wall polymers, terpenoid backbone synthesis, iron metabolism and transport, and cell division. That many genes are rapidly differentially expressed upon transfer of cells from a planktonic to an immobilized state suggests that cells experience the two environments differently. It seems possible that surface contact initiates anticipatory changes in P. syringae gene expression, which enables rapid and appropriate physiological responses to the different environmental conditions such as might occur in a biofilm. Such responses could help cells survive transitions from aquatic habitats fostering planktonic traits to attachment on surfaces, conditions that alternatively occur on leaves.
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Qi SS, Bogdanov A, Cnockaert M, Acar T, Ranty-Roby S, Coenye T, Vandamme P, König GM, Crüsemann M, Carlier A. Induction of antibiotic specialized metabolism by co-culturing in a collection of phyllosphere bacteria. Environ Microbiol 2021; 23:2132-2151. [PMID: 33393154 DOI: 10.1111/1462-2920.15382] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/29/2020] [Indexed: 01/04/2023]
Abstract
A diverse set of bacteria live on the above-ground parts of plants, composing the phyllosphere, and play important roles for plant health. Phyllosphere microbial communities assemble in a predictable manner and diverge from communities colonizing other plant organs or the soil. However, how these communities differ functionally remains obscure. We assembled a collection of 258 bacterial isolates representative of the most abundant taxa of the phyllosphere of Arabidopsis and a shared soil inoculum. We screened the collection for the production of metabolites that inhibit the growth of Gram-positive and Gram-negative bacteria either in isolation or in co-culture. We found that isolates capable of constitutive antibiotic production in monoculture were significantly enriched in the soil fraction. In contrast, the proportion of binary cultures resulting in the production of growth inhibitory compounds differed only marginally between the phyllosphere and soil fractions. This shows that the phyllosphere may be a rich resource for potentially novel molecules with antibiotic activity, but that production or activity is dependent upon induction by external signals or cues. Finally, we describe the isolation of antimicrobial acyloin metabolites from a binary culture of Arabidopsis phyllosphere isolates, which inhibit the growth of clinically relevant Acinetobacter baumannii.
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Affiliation(s)
- Shan Shan Qi
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Alexander Bogdanov
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, Bonn, 53115, Germany.,Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California
| | - Margo Cnockaert
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Tessa Acar
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium.,LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Sarah Ranty-Roby
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Peter Vandamme
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, Bonn, 53115, Germany
| | - Max Crüsemann
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, Bonn, 53115, Germany
| | - Aurélien Carlier
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium.,LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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Grapevine Microbiota Reflect Diversity among Compartments and Complex Interactions within and among Root and Shoot Systems. Microorganisms 2021; 9:microorganisms9010092. [PMID: 33401756 PMCID: PMC7823683 DOI: 10.3390/microorganisms9010092] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/15/2022] Open
Abstract
Grafting connects root and shoot systems of distinct individuals, bringing microbial communities of different genotypes together in a single plant. How do root system and shoot system genotypes influence plant microbiota in grafted grapevines? To address this, we utilized clonal replicates of the grapevine ‘Chambourcin’, growing ungrafted and grafted to three different rootstocks in three irrigation treatments. Our objectives were to (1) characterize the microbiota (bacteria and fungi) of below-ground compartments (roots, adjacent soil) and above-ground compartments (leaves, berries), (2) determine how rootstock genotype, irrigation, and their interaction influences grapevine microbiota in different compartments, and (3) investigate abundance of microorganisms implicated in the late-season grapevine disease sour rot (Acetobacterales and Saccharomycetes). We found that plant compartment had the largest influence on microbial diversity. Neither rootstock genotype nor irrigation significantly influenced microbial diversity or composition. However, differential abundance of bacterial and fungal taxa varied as a function of rootstock and irrigation treatment; in particular, Acetobacterales and Saccharomycetes displayed higher relative abundance in berries of grapevines grafted to ‘1103P’ and ‘SO4’ rootstocks and varied across irrigation treatments. This study demonstrates that grapevine compartments retain distinct microbiota and identifies associations between rootstock genotypes, irrigation treatment, and the relative abundance of agriculturally relevant microorganisms in the berries.
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Hayes RA, Rebolleda‐Gómez M, Butela K, Cabo LF, Cullen N, Kaufmann N, O'Neill S, Ashman T. Spatially explicit depiction of a floral epiphytic bacterial community reveals role for environmental filtering within petals. Microbiologyopen 2021; 10:e1158. [PMID: 33650801 PMCID: PMC7859501 DOI: 10.1002/mbo3.1158] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/04/2023] Open
Abstract
The microbiome of flowers (anthosphere) is an understudied compartment of the plant microbiome. Within the flower, petals represent a heterogeneous environment for microbes in terms of resources and environmental stress. Yet, little is known of drivers of structure and function of the epiphytic microbial community at the within-petal scale. We characterized the petal microbiome in two co-flowering plants that differ in the pattern of ultraviolet (UV) absorption along their petals. Bacterial communities were similar between plant hosts, with only rare phylogenetically distant species contributing to differences. The epiphyte community was highly culturable (75% of families) lending confidence in the spatially explicit isolation and characterization of bacteria. In one host, petals were heterogeneous in UV absorption along their length, and in these, there was a negative relationship between growth rate and position on the petal, as well as lower UV tolerance in strains isolated from the UV-absorbing base than from UV reflecting tip. A similar pattern was not seen in microbes isolated from a second host whose petals had uniform patterning along their length. Across strains, the variation in carbon usage and chemical tolerance followed common phylogenetic patterns. This work highlights the value of petals for spatially explicit explorations of bacteria of the anthosphere.
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Affiliation(s)
- Rebecca A. Hayes
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Maria Rebolleda‐Gómez
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenCTUSA
| | - Kristen Butela
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Leah F. Cabo
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Nevin Cullen
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Nancy Kaufmann
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Steffani O'Neill
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
| | - Tia‐Lynn Ashman
- Department of Biological SciencesUniversity of PittsburghPittsburghPAUSA
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Xiang Q, Lott AA, Assmann SM, Chen S. Advances and perspectives in the metabolomics of stomatal movement and the disease triangle. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 302:110697. [PMID: 33288010 DOI: 10.1016/j.plantsci.2020.110697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 05/20/2023]
Abstract
Crops are continuously exposed to microbial pathogens that cause tremendous yield losses worldwide. Stomatal pores formed by pairs of specialized guard cells in the leaf epidermis represent a major route of pathogen entry. Guard cells have an essential role as a first line of defense against pathogens. Metabolomics is an indispensable systems biology tool that has facilitated discovery and functional studies of metabolites that regulate stomatal movement in response to pathogens and other environmental factors. Guard cells, pathogens and environmental factors constitute the "stomatal disease triangle". The aim of this review is to highlight recent advances toward understanding the stomatal disease triangle in the context of newly discovered signaling molecules, hormone crosstalk, and consequent molecular changes that integrate pathogens and environmental sensing into stomatal immune responses. Future perspectives on emerging single-cell studies, multiomics and molecular imaging in the context of stomatal defense are discussed. Advances in this important area of plant biology will inform rational crop engineering and breeding for enhanced stomatal defense without disruption of other pathways that impact crop yield.
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Affiliation(s)
- Qingyuan Xiang
- Department of Biology, University of Florida Genetics Institute, Gainesville, FL, USA
| | - Aneirin A Lott
- Department of Biology, University of Florida Genetics Institute, Gainesville, FL, USA; Plant Molecular and Cellular Biology Program, University of Florida, FL, USA
| | - Sarah M Assmann
- Department of Biology, Pennsylvania State University, State College, PA, USA
| | - Sixue Chen
- Department of Biology, University of Florida Genetics Institute, Gainesville, FL, USA; Plant Molecular and Cellular Biology Program, University of Florida, FL, USA; Proteomics and Mass Spectrometry Facility, University of Florida, FL, USA.
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Shakir S, Zaidi SSEA, de Vries FT, Mansoor S. Plant Genetic Networks Shaping Phyllosphere Microbial Community. Trends Genet 2020; 37:306-316. [PMID: 33036802 DOI: 10.1016/j.tig.2020.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 12/14/2022]
Abstract
Phyllosphere microbial communities inhabit the aerial plant parts, such as leaves and flowers, where they form complex molecular interactions with the host plant. Contrary to the relatively well-studied rhizosphere microbiome, scientists are just starting to understand, and potentially utilize, the phyllosphere microbiome. In this article, we summarize the recent studies that have provided novel insights into the mechanism of the host genotype shaping the phyllosphere microbiome and the possibility to select a stable and well-adapted microbiome. We also discuss the most pressing gaps in our knowledge and identify the most promising research directions and tools for understanding the assembly and function of phyllosphere microbiomes - this understanding is necessary if we are to harness phyllosphere microbiomes for improving plant growth and health in managed systems.
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Affiliation(s)
- Sara Shakir
- Plant Genetics, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Syed Shan-E-Ali Zaidi
- Plant Genetics, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Franciska T de Vries
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan.
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