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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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2
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Dong M, Kavannaugh M, Lee C, Feng H. Mircrofabricating double-sided polydimethylsiloxane (PDMS) artificial phylloplane for microbial food safety research. Food Res Int 2024; 184:114252. [PMID: 38609230 DOI: 10.1016/j.foodres.2024.114252] [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: 12/10/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/14/2024]
Abstract
Leafy green surface microbiology studies often experience significant variations in results due to the heterogeneous nature of leaf surfaces. To provide a precise and controllable substitute, we microfabricated double-sided artificial leafy green phylloplanes using polydimethylsiloxane (PDMS) with a vinyl-terminated polyethylene glycol chain-based hydrophobicity modifier (PDMS-PEG) to modify PDMS hydrophobicity. We further tested the properties and applications of these artificial leaves, by examining the function of epicuticular wax, growth and survival of E. coli O157:H7 87-23 on the surface, and removal of attached E. coli cells via sanitation. The double-sided PDMS-PDMS-PEG leaves well-replicated their natural counterparts in macroscopic and microscopic structure, hydrophobicity, and E. coli O157:H7 87-23 attachment. After depositing natural epicuticular wax onto artificial leaves, the leaf surface wetting ability decreased, while E. coli O157:H7 87-23 surface retention increased. The artificial leaves supplied with lettuce lysate or bacterial growth media supported E. coli O157:H7 87-23 growth and survival similarly to those on natural leaves. In the sanitation test, the artificial lettuce leaves also displayed patterns similar to those of natural leaves regarding sanitizer efficiency. Overall, this study showcased the microfabrication and applications of double-sided PDMS-PDMS-PEG leaves as a replicable and controllable platform for future leafy green food safety studies.
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Affiliation(s)
- Mengyi Dong
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| | - Melannie Kavannaugh
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| | - Caroline Lee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| | - Hao Feng
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Family and Consumer Sciences, North Carolina Agriculture and Technology State University, Greensboro, NC 27401, United States.
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3
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Degnan RM, McTaggart AR, Shuey LS, Pame LJS, Smith GR, Gardiner DM, Nock V, Soffe R, Sale S, Garrill A, Carroll BJ, Mitter N, Sawyer A. Exogenous double-stranded RNA inhibits the infection physiology of rust fungi to reduce symptoms in planta. MOLECULAR PLANT PATHOLOGY 2023; 24:191-207. [PMID: 36528383 PMCID: PMC9923395 DOI: 10.1111/mpp.13286] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 06/01/2023]
Abstract
Rust fungi (Pucciniales) are a diverse group of plant pathogens in natural and agricultural systems. They pose ongoing threats to the diversity of native flora and cause annual crop yield losses. Agricultural rusts are predominantly managed with fungicides and breeding for resistance, but new control strategies are needed on non-agricultural plants and in fragile ecosystems. RNA interference (RNAi) induced by exogenous double-stranded RNA (dsRNA) has promise as a sustainable approach for managing plant-pathogenic fungi, including rust fungi. We investigated the mechanisms and impact of exogenous dsRNA on rust fungi through in vitro and whole-plant assays using two species as models, Austropuccinia psidii (the cause of myrtle rust) and Coleosporium plumeriae (the cause of frangipani rust). In vitro, dsRNA either associates externally or is internalized by urediniospores during the early stages of germination. The impact of dsRNA on rust infection architecture was examined on artificial leaf surfaces. dsRNA targeting predicted essential genes significantly reduced germination and inhibited development of infection structures, namely appressoria and penetration pegs. Exogenous dsRNA sprayed onto 1-year-old trees significantly reduced myrtle rust symptoms. Furthermore, we used comparative genomics to assess the wide-scale amenability of dsRNA to control rust fungi. We sequenced genomes of six species of rust fungi, including three new families (Araucariomyceaceae, Phragmidiaceae, and Skierkaceae) and identified key genes of the RNAi pathway across 15 species in eight families of Pucciniales. Together, these findings indicate that dsRNA targeting essential genes has potential for broad-use management of rust fungi across natural and agricultural systems.
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Affiliation(s)
- Rebecca M. Degnan
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt LuciaQueenslandAustralia
| | - Alistair R. McTaggart
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural ScienceThe University of QueenslandSt LuciaQueenslandAustralia
| | - Louise S. Shuey
- Queensland Department of Agriculture and FisheriesEcosciences PrecinctDutton ParkQueenslandAustralia
| | - Leny Jane S. Pame
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt LuciaQueenslandAustralia
| | - Grant R. Smith
- The New Zealand Institute for Plant and Food Research LimitedLincolnNew Zealand
| | - Donald M. Gardiner
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural ScienceThe University of QueenslandSt LuciaQueenslandAustralia
| | - Volker Nock
- Department of Electrical and Computer EngineeringUniversity of CanterburyChristchurchNew Zealand
| | - Rebecca Soffe
- Department of Electrical and Computer EngineeringUniversity of CanterburyChristchurchNew Zealand
- Present address:
School of EngineeringRMIT UniversityMelbourneVictoriaAustralia
| | - Sarah Sale
- Department of Electrical and Computer EngineeringUniversity of CanterburyChristchurchNew Zealand
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
| | - Ashley Garrill
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
| | - Bernard J. Carroll
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt LuciaQueenslandAustralia
| | - Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural ScienceThe University of QueenslandSt LuciaQueenslandAustralia
| | - Anne Sawyer
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt LuciaQueenslandAustralia
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural ScienceThe University of QueenslandSt LuciaQueenslandAustralia
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4
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Wright KM, Wright PJ, Holden NJ. Plant species-dependent transmission of Escherichia coli O157:H7 from the spermosphere to cotyledons and first leaves. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:926-933. [PMID: 35968609 PMCID: PMC9804575 DOI: 10.1111/1758-2229.13115] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
The colonization of six edible plant species: alfalfa, broccoli, coriander, lettuce, parsley and rocket, by the human pathogen Shigatoxigenic Escherichia coli was investigated following two modes of artificial inoculation of seeds, by soaking or watering. The frequency and extent of colonization of cotyledons depended on the mode of inoculation, with three, rapidly germinating species being successfully colonized after overnight soaking, but slower germinating species requiring prolonged exposure to bacteria by watering of the surrounding growth media. Separate analysis of the cotyledons and leaves from individual plants highlighted that successful colonization of the true leaves was also species dependent. For three species, failure of transfer, or lack of nutrients or suitable microhabitat on the leaf surface resulted in infrequent bacterial colonization. Colonization of leaves was lower and generally in proportion to that in cotyledons, if present. The potential risks associated with consumption of leafy produce are discussed.
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Affiliation(s)
| | | | - Nicola Jean Holden
- The James Hutton InstituteInvergowrie, DundeeUK
- SRUC, Department of Rural Land Use, Craibstone EstateAberdeenUK
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5
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Rombach H, Alon H, Shapiro OH, Elad Y, Kleiman M. Elucidating the effect of tomato leaf surface microstructure on Botrytis cinerea using synthetic systems. FRONTIERS IN PLANT SCIENCE 2022; 13:1023502. [PMID: 36388570 PMCID: PMC9650585 DOI: 10.3389/fpls.2022.1023502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
For some pathogenic fungi, sensing surface topography is part of their infection strategy. Their directional growth and transformation to a new developmental stage is influenced by contact with topographic features, which is referred to as thigmo-response, the exact functionality of which is not fully understood. Research on thigmo-responses is often performed on biomimetically patterned surfaces (BPS). Polydimethylsiloxane (PDMS) is especially suitable for fabrication of BPS. Here, we used synthetic BPS surfaces, mimicking tomato leaf surface, made from PDMS with the pathogenic fungus Botrytis cinerea to study the influence of structural features of the leaf surface on the fungus behavior. As a control, a PDMS surface without microstructure was fabricated to maintain the same chemical properties. Pre-penetration processes of B. cinerea, including the distribution of conidia on the surface, germination, and germ tube growth were observed on both leaf-patterned and flat PDMS. Microstructure affected the location of immediate attachment of conidia. Additionally, the microstructure of the plant host stimulated the development of germ tube in B. cinerea, at a higher rate than that observed on flat surface, suggesting that microstructure plays a role in fungus attachment and development.
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Affiliation(s)
- Helen Rombach
- Department of Agriculture and Horticulture, Humboldt University Zu Berlin, Berlin, Germany
- Institute of Plant Sciences, Department of Vegetables and Field Crops, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
| | - Haguy Alon
- Institute of Plant Sciences, Department of Vegetables and Field Crops, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
- Inter-Faculty Graduate Biotechnology Program, the Hebrew University of Jerusalem, Rehovot, Israel
| | - Orr H. Shapiro
- Institute of Postharvest and Food Sciences, Department of Food Sciences, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
| | - Yigal Elad
- Institute of Plant Protection, Department of Plant Pathology and Weed Research, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
| | - Maya Kleiman
- Institute of Plant Sciences, Department of Vegetables and Field Crops, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
- Agro-Nano Technology and Advanced Materials Center, Agricultural Research Organization (Volcani Center), Rishon Lezion, Israel
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6
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Huth MA, Huth A, Schreiber L, Koch K. Design of a biomimetic, small-scale artificial leaf surface for the study of environmental interactions. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:944-957. [PMID: 36161251 PMCID: PMC9490070 DOI: 10.3762/bjnano.13.83] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/16/2022] [Indexed: 06/16/2023]
Abstract
The cuticle with its superimposed epicuticular waxes represents the barrier of all aboveground parts of higher plant primary tissues. Epicuticular waxes have multiple effects on the interaction of plants with their living and non-living environment, whereby their shape, dimension, arrangement, and chemical composition play significant roles. Here, the ability of self-assembly of wax after isolation from the leaves was used to develop a small-scale wax-coated artificial leaf surface with the chemical composition and wettability of wheat (Triticum aestivum) leaves. By thermal evaporation of extracted plant waxes and adjustment of the evaporated wax amounts, the wettability and chemical character of the microstructure of the surface of wheat leaves were transferred onto a technical surface. For the use of these artificial leaves as a test system for biotic (e.g., germination of fungal pathogens) and non-biotic (e.g., applied surfactants) interactions on natural leaf surfaces, the chemical composition and the wetting behavior should be the same in both. Therefore, the morphology, chemistry, and wetting properties of natural and artificial surfaces with recrystallized wax structures were analyzed by scanning electron microscopy, gas chromatography-mass spectrometry, and by the determination of water contact angles, contact angle hysteresis, and tilting angles. Wheat leaves of different ages were covered exclusively with wax platelets. The extracted wheat wax was composed of alcohols, aldehydes, esters, and acids. The main component was 1-octacosanol. The waxes recrystallized as three-dimensional structures on the artificial surfaces. The three tested wetting parameters resembled the ones of the natural surface, providing an artificial surface with the chemical information of epicuticular waxes and the wetting properties of a natural leaf surface.
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Affiliation(s)
- Miriam Anna Huth
- Faculty of Life Sciences, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany
| | - Axel Huth
- Faculty of Life Sciences, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany
| | - Lukas Schreiber
- IZMB, Department of Ecophysiology, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Kerstin Koch
- Faculty of Life Sciences, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany
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7
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Ranjbaran M, Verma MS. Microfluidics at the interface of bacteria and fresh produce. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Yi J, Leveau JH, Nitin N. Role of multiscale leaf surface topography in antimicrobial efficacy of chlorine-based sanitizers. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2022.111118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Fessia A, Barra P, Barros G, Nesci A. Could Bacillus biofilms enhance the effectivity of biocontrol strategies in the phyllosphere? J Appl Microbiol 2022; 133:2148-2166. [PMID: 35476896 DOI: 10.1111/jam.15596] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/13/2022] [Accepted: 04/21/2022] [Indexed: 11/30/2022]
Abstract
Maize (Zea mays L.), a major crop in Argentina and a staple food around the world, is affected by the emergence and re-emergence of foliar diseases. Agrochemicals are the main control strategy nowadays, but they can cause resistance in insects and microbial pathogens and have negative effects on the environment and human health. An emerging alternative is the use of living organisms, i.e. microbial biocontrol agents, to suppress plant pathogen populations. This is a risk-free approach when the organisms acting as biocontrol agents come from the same ecosystem as the foliar pathogens they are meant to antagonize. Some epiphytic microorganisms may form biofilm by becoming aggregated and attached to a surface, as is the case of spore-forming bacteria from the genus Bacillus. Their ability to sporulate and their tolerance to long storage periods make them a frequently used biocontrol agent. Moreover, the biofilm that they create protects them against different abiotic and biotic factors and helps them to acquire nutrients, which ensures their survival on the plants they protect. This review analyzes the interactions that the phyllosphere-inhabiting Bacillus genus establishes with its environment through biofilm, and how this lifestyle could serve to design effective biological control strategies.
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Affiliation(s)
- Aluminé Fessia
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Paula Barra
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Germán Barros
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Andrea Nesci
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
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10
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Gilbert KJ, Renner T. Acid or base? How do plants regulate the ecology of their phylloplane? AOB PLANTS 2021; 13:plab032. [PMID: 34285793 PMCID: PMC8286713 DOI: 10.1093/aobpla/plab032] [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: 11/23/2020] [Accepted: 05/25/2021] [Indexed: 05/29/2023]
Abstract
Plants interface with and modify the external environment across their surfaces, and in so doing, can control or mitigate the impacts of abiotic stresses and also mediate their interactions with other organisms. Botanically, it is known that plant roots have a multi-faceted ability to modify rhizosphere conditions like pH, a factor with a large effect on a plant's biotic interactions with microbes. But plants can also modify pH levels on the surfaces of their leaves. Plants can neutralize acid rain inputs in a period of hours, and either acidify or alkalinize the pH of neutral water droplets in minutes. The pH of the phylloplane-that is, the outermost surface of the leaf-varies across species, from incredibly acidic (carnivorous plants: as low as pH 1) to exceptionally alkaline (species in the plant family, Malvaceae, up to pH 11). However, most species mildly acidify droplets on the phylloplane by 1.5 orders of magnitude in pH. Just as rhizosphere pH helps shape the plant microbiome and is known to influence belowground interactions, so too can phylloplane pH influence aboveground interactions in plant canopies. In this review, we discuss phylloplane pH regulation from the physiological, molecular, evolutionary, and ecological perspectives and address knowledge gaps and identify future research directions.
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Affiliation(s)
- Kadeem J Gilbert
- Department of Entomology, The Pennsylvania State University, 501 Agricultural Sciences and Industries Building, University Park, PA 16802, USA
| | - Tanya Renner
- Department of Entomology, The Pennsylvania State University, 501 Agricultural Sciences and Industries Building, University Park, PA 16802, USA
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11
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Kumari P, Sayas T, Bucki P, Brown-Miyara S, Kleiman M. Real-Time Visualization of Cellulase Activity by Microorganisms on Surface. Int J Mol Sci 2020; 21:ijms21186593. [PMID: 32916923 PMCID: PMC7555966 DOI: 10.3390/ijms21186593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 01/03/2023] Open
Abstract
A variety of methods to detect cellulase secretion by microorganisms has been developed over the years, none of which enables the real-time visualization of cellulase activity on a surface. This visualization is critical to study the interaction between soil-borne cellulase-secreting microorganisms and the surface of plant roots and specifically, the effect of surface features on this interaction. Here, we modified the known carboxymethyl cellulase (CMC) hydrolysis visualization method to enable the real-time tracking of cellulase activity of microorganisms on a surface. A surface was formed using pure CMC with acridine orange dye incorporated in it. The dye disassociated from the film when hydrolysis occurred, forming a halo surrounding the point of hydrolysis. This enabled real-time visualization, since the common need for post hydrolysis dyeing was negated. Using root-knot nematode (RKN) as a model organism that penetrates plant roots, we showed that it was possible to follow microorganism cellulase secretion on the surface. Furthermore, the addition of natural additives was also shown to be an option and resulted in an increased RKN response. This method will be implemented in the future, investigating different microorganisms on a root surface microstructure replica, which can open a new avenue of research in the field of plant root-microorganism interactions.
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Affiliation(s)
- Pallavi Kumari
- Institute of Plant Sciences, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel; (P.K.); (T.S.)
| | - Tali Sayas
- Institute of Plant Sciences, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel; (P.K.); (T.S.)
| | - Patricia Bucki
- Institute of Plant Protection, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel; (P.B.); (S.B.-M.)
| | - Sigal Brown-Miyara
- Institute of Plant Protection, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel; (P.B.); (S.B.-M.)
| | - Maya Kleiman
- Institute of Plant Sciences, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel; (P.K.); (T.S.)
- Agro-NanoTechnology and Advanced Materials Center, Agricultural Research Organization (Volcani Center), Rishon Lezion 7505101, Israel
- Correspondence:
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12
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Moitinho MA, Souza DT, Chiaramonte JB, Bononi L, Melo IS, Taketani RG. The unexplored bacterial lifestyle on leaf surface. Braz J Microbiol 2020; 51:1233-1240. [PMID: 32363565 PMCID: PMC7455623 DOI: 10.1007/s42770-020-00287-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 04/25/2020] [Indexed: 01/19/2023] Open
Abstract
Social interactions impact microbial communities and these relationships are mediated by small molecules. The chemical ecology of bacteria on the phylloplane environment is still little explored. The harsh environmental conditions found on leaf surface require high metabolic performances of the bacteria in order to survive. That is interesting both for scientific fields of prospecting natural molecules and for the ecological studies. Important queries about the bacterial lifestyle on leaf surface remain not fully comprehended. Does the hostility of the environment increase the populations' cellular altruism by the production of molecules, which can benefit the whole community? Or does the reverse occur and the production of molecules related to competition between species is increased? Does the phylogenetic distance between the bacterial populations influence the chemical profile during social interactions? Do phylogenetically related bacteria tend to cooperate more than the distant ones? The phylloplane contains high levels of yet uncultivated microorganisms, and understanding the molecular basis of the social networks on this habitat is crucial to gain new insights on the ecology of the mysterious community members due to interspecies molecular dependence. Here, we review and discuss what is known about bacterial social interactions and their chemical lifestyle on leaf surface.
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Affiliation(s)
- Marta A Moitinho
- Laboratory of Environmental Microbiology, EMBRAPA Environment, Brazilian Agricultural Research Corporation, SP 340, Km 127.5, Jaguariúna, São Paulo, 13820-000, Brazil
- College of Agriculture Luiz de Queiroz, University of São Paulo, Av. Pádua Dias, 11, Piracicaba, São Paulo, 13418-900, Brazil
| | - Danilo T Souza
- Laboratory of Mass Spectrometry Applied Natural Products Chemistry; Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, São Paulo, 14040-901, Brazil
| | - Josiane B Chiaramonte
- Laboratory of Environmental Microbiology, EMBRAPA Environment, Brazilian Agricultural Research Corporation, SP 340, Km 127.5, Jaguariúna, São Paulo, 13820-000, Brazil
- College of Agriculture Luiz de Queiroz, University of São Paulo, Av. Pádua Dias, 11, Piracicaba, São Paulo, 13418-900, Brazil
| | - Laura Bononi
- Laboratory of Environmental Microbiology, EMBRAPA Environment, Brazilian Agricultural Research Corporation, SP 340, Km 127.5, Jaguariúna, São Paulo, 13820-000, Brazil
- College of Agriculture Luiz de Queiroz, University of São Paulo, Av. Pádua Dias, 11, Piracicaba, São Paulo, 13418-900, Brazil
| | - Itamar S Melo
- Laboratory of Environmental Microbiology, EMBRAPA Environment, Brazilian Agricultural Research Corporation, SP 340, Km 127.5, Jaguariúna, São Paulo, 13820-000, Brazil
| | - Rodrigo G Taketani
- College of Agriculture Luiz de Queiroz, University of São Paulo, Av. Pádua Dias, 11, Piracicaba, São Paulo, 13418-900, Brazil.
- CETEM, Centre for Mineral Technology, MCTIC Ministry of Science, Technology, Innovation and Communication, Av. Pedro Calmon, 900, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, 21941-908, Brazil.
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13
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Doan HK, Antequera-Gómez ML, Parikh AN, Leveau JHJ. Leaf Surface Topography Contributes to the Ability of Escherichia coli on Leafy Greens to Resist Removal by Washing, Escape Disinfection With Chlorine, and Disperse Through Splash. Front Microbiol 2020; 11:1485. [PMID: 32765440 PMCID: PMC7380079 DOI: 10.3389/fmicb.2020.01485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 06/08/2020] [Indexed: 12/25/2022] Open
Abstract
The attachment of foodborne pathogens to leaf surfaces is a complex process that involves multiple physical, chemical, and biological factors. Here, we report the results from a study designed to specifically determine the contribution of spinach leaf surface topography as it relates to leaf axis (abaxial and adaxial) and leaf age (15, 45, and 75 days old) to the ability of Escherichia coli to resist removal by surface wash, to avoid inactivation by chlorine, and to disperse through splash impact. We used fresh spinach leaves, as well as so-called "replicasts" of spinach leaf surfaces in the elastomer polydimethylsiloxane to show that leaf vein density correlated positively with the failure to recover E. coli from surfaces, not only using a simple water wash and rinse, but also a more stringent wash protocol involving a detergent. Such failure was more pronounced when E. coli was surface-incubated at 24°C compared to 4°C, and in the presence, rather than absence, of nutrients. Leaf venation also contributed to the ability of E. coli to survive a 50 ppm available chlorine wash and to laterally disperse by splash impact. Our findings suggest that the topographical properties of the leafy green surface, which vary by leaf age and axis, may need to be taken into consideration when developing prevention or intervention strategies to enhance the microbial safety of leafy greens.
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Affiliation(s)
- Hung K. Doan
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| | - María L. Antequera-Gómez
- Departamento de Microbiología, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Atul N. Parikh
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States
- Department of Materials Science and Engineering, University of California, Davis, Davis, CA, United States
| | - Johan H. J. Leveau
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
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14
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Abstract
Microscopic water films allow bacteria to survive the seemingly dry surface of plant leaves.
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Affiliation(s)
- Robin Tecon
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
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15
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Grinberg M, Orevi T, Steinberg S, Kashtan N. Bacterial survival in microscopic surface wetness. eLife 2019; 8:e48508. [PMID: 31610846 PMCID: PMC6824842 DOI: 10.7554/elife.48508] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/20/2019] [Indexed: 01/06/2023] Open
Abstract
Plant leaves constitute a huge microbial habitat of global importance. How microorganisms survive the dry daytime on leaves and avoid desiccation is not well understood. There is evidence that microscopic surface wetness in the form of thin films and micrometer-sized droplets, invisible to the naked eye, persists on leaves during daytime due to deliquescence - the absorption of water until dissolution - of hygroscopic aerosols. Here, we study how such microscopic wetness affects cell survival. We show that, on surfaces drying under moderate humidity, stable microdroplets form around bacterial aggregates due to capillary pinning and deliquescence. Notably, droplet-size increases with aggregate-size, and cell survival is higher the larger the droplet. This phenomenon was observed for 13 bacterial species, two of which - Pseudomonas fluorescens and P. putida - were studied in depth. Microdroplet formation around aggregates is likely key to bacterial survival in a variety of unsaturated microbial habitats, including leaf surfaces.
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Affiliation(s)
- Maor Grinberg
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Tomer Orevi
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Shifra Steinberg
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Nadav Kashtan
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
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16
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Soffe R, Bernach M, Remus-Emsermann MNP, Nock V. Replicating Arabidopsis Model Leaf Surfaces for Phyllosphere Microbiology. Sci Rep 2019; 9:14420. [PMID: 31595008 PMCID: PMC6783459 DOI: 10.1038/s41598-019-50983-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/23/2019] [Indexed: 12/20/2022] Open
Abstract
Artificial surfaces are commonly used in place of leaves in phyllosphere microbiology to study microbial behaviour on plant leaf surfaces. These surfaces enable a reductionist approach to be undertaken, to enable individual environmental factors influencing microorganisms to be studied. Commonly used artificial surfaces include nutrient agar, isolated leaf cuticles, and reconstituted leaf waxes. Recently, replica surfaces mimicking the complex topography of leaf surfaces for phyllosphere microbiology studies are appearing in literature. Replica leaf surfaces have been produced in agar, epoxy, polystyrene, and polydimethylsiloxane (PDMS). However, none of these protocols are suitable for replicating fragile leaves such as of the model plant Arabidopsis thaliana. This is of importance, as A. thaliana is a model system for molecular plant genetics, molecular plant biology, and microbial ecology. To overcome this limitation, we introduce a versatile replication protocol for replicating fragile leaf surfaces into PDMS. Here we demonstrate the capacity of our replication process using optical microscopy, atomic force microscopy (AFM), and contact angle measurements to compare living and PDMS replica A. thaliana leaf surfaces. To highlight the use of our replica leaf surfaces for phyllosphere microbiology, we visualise bacteria on the replica leaf surfaces in comparison to living leaf surfaces.
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Affiliation(s)
- Rebecca Soffe
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand.
| | - Michal Bernach
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Volker Nock
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand.
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17
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Hýsek J, Vavera R, Růžek P. Cultivation Intensity in Combination with Other Ecological Factors as Limiting Ones for the Abundance of Phytopathogenic Fungi on Wheat. MICROBIAL ECOLOGY 2019; 78:565-574. [PMID: 30895363 DOI: 10.1007/s00248-019-01337-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
In field and laboratory experiments during 2014-2017, we investigated the influence of lower and higher cultivation intensity of wheat and ecological factors (weather-temperature and rainfalls, year) on the occurrence of phytopathogenic fungi on the leaves of winter wheat. The prevailing fungi in those years were Mycosphaerella graminicola (Fuckel) J. Schrott and Pyrenophora tritici-repentis (Died.) Drechsler. Using cluster analysis, we statistically evaluated interrelationships of known factors on the abundance of the fungi on leaf surfaces. Our results showed strongest correlation with Mycosphaerella graminicola and Pyrenophora tritici-repentis abundance to be with lower cultivation intensity and year done by the temperature and the rainfalls. The two pathogens-Puccinia tritici Oerst and Hymenula cerealis Ellis & Everh. occurred only very sparsely in some years and had little positive or negative correlation with named factors. The semi-early and semi-late winter wheat varieties Matchball, Annie, Fakir, and Tobak were used for our experiments. Higher cultivation intensity had protective effect against leaf phytopathogenic fungi.
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Affiliation(s)
- Josef Hýsek
- Crop Research Institute (CRI), Ruzyně, Prague 6, Czech Republic.
| | - Radek Vavera
- Crop Research Institute (CRI), Ruzyně, Prague 6, Czech Republic
| | - Pavel Růžek
- Crop Research Institute (CRI), Ruzyně, Prague 6, Czech Republic
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18
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Schlechter RO, Miebach M, Remus-Emsermann MN. Driving factors of epiphytic bacterial communities: A review. J Adv Res 2019; 19:57-65. [PMID: 31341670 PMCID: PMC6630024 DOI: 10.1016/j.jare.2019.03.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/29/2022] Open
Abstract
Bacteria establish complex, compositionally consistent communities on healthy leaves. Ecological processes such as dispersal, diversification, ecological drift, and selection as well as leaf surface physicochemistry and topology impact community assembly. Since the leaf surface is an oligotrophic environment, species interactions such as competition and cooperation may be major contributors to shape community structure. Furthermore, the plant immune system impacts on microbial community composition, as plant cells respond to bacterial molecules and shape their responses according to the mixture of molecules present. Such tunability of the plant immune network likely enables the plant host to differentiate between pathogenic and non-pathogenic colonisers, avoiding costly immune responses to non-pathogenic colonisers. Plant immune responses are either systemically distributed or locally confined, which in turn affects the colonisation pattern of the associated microbiota. However, how each of these factors impacts the bacterial community is unclear. To better understand this impact, bacterial communities need to be studied at a micrometre resolution, which is the scale that is relevant to the members of the community. Here, current insights into the driving factors influencing the assembly of leaf surface-colonising bacterial communities are discussed, with a special focus on plant host immunity as an emerging factor contributing to bacterial leaf colonisation.
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Affiliation(s)
- Rudolf O. Schlechter
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Moritz Miebach
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Mitja N.P. Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
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19
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Comparison of replica leaf surface materials for phyllosphere microbiology. PLoS One 2019; 14:e0218102. [PMID: 31170240 PMCID: PMC6553772 DOI: 10.1371/journal.pone.0218102] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/27/2019] [Indexed: 12/25/2022] Open
Abstract
Artificial surfaces are routinely used instead of leaves to enable a reductionist approach in phyllosphere microbiology, the study of microorganisms residing on plant leaf surfaces. Commonly used artificial surfaces include, flat surfaces, such as metal and nutrient agar, and microstructured surfaces, such as isolate leaf cuticles or reconstituted leaf waxes. However, interest in replica leaf surfaces as an artificial surface is growing, as replica surfaces provide an improved representation of the complex topography of leaf surfaces. To date, leaf surfaces have predominantly been replicated for their superhydrophobic properties. In contrast, in this paper we investigated the potential of agarose, the elastomer polydimethylsiloxane (PDMS), and gelatin as replica leaf surface materials for phyllosphere microbiology studies. Using a test pattern of pillars, we investigated the ability to replicate microstructures into the materials, as well as the degradation characteristics of the materials in environmental conditions. Pillars produced in PDMS were measured to be within 10% of the mold master and remained stable throughout the degradation experiments. In agarose and gelatin the pillars deviated by more than 10% and degraded considerably within 48 hours in environmental conditions. Furthermore, we investigated the surface energy of the materials, an important property of a leaf surface, which influences resource availability and microorganism attachment. We found that the surface energy and bacterial viability on PDMS was comparable to isolated Citrus × aurantium and Populus × canescens leaf cuticles. Hence indicating that PDMS is the most suitable material for replica leaf surfaces. In summary, our experiments highlight the importance of considering the inherent material properties when selecting a replica leaf surface for phyllosphere microbiology studies. As demonstrated, a PDMS replica leaf offers a control surface that can be used for investigating microbe-microbe and microbe-plant interactions in the phyllosphere, which will enable mitigation strategies against pathogens to be developed.
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20
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Remus-Emsermann MNP, Schlechter RO. Phyllosphere microbiology: at the interface between microbial individuals and the plant host. THE NEW PHYTOLOGIST 2018; 218:1327-1333. [PMID: 29504646 DOI: 10.1111/nph.15054] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/12/2018] [Indexed: 05/18/2023]
Abstract
Contents Summary 1327 I. Introduction 1327 II. Individuality and the relevance of scales for the investigation of bacteria 1328 III. Bacterial aggregation and community patterning at the single-cell resolution 1329 IV. What are the effects on the plant host? 1330 V. Future directions and current questions 1331 Acknowledgements 1332 ORCID 1332 References 1332 SUMMARY: Leaf surfaces are home to diverse bacterial communities. Within these communities, every individual cell perceives its unique environment and responds accordingly. In this insight article, the perspective of the bacterial individual is assumed in an attempt to describe how the spatially heterogeneous leaf surface determines the fate of bacteria. To investigate behaviour at scales relevant to bacteria, single-cell approaches are essential. Single-cell studies provide important lessons about how current 'omics' approaches fail to give an accurate picture of the behaviour of bacterial populations in heterogeneous environments. Upcoming techniques will soon allow us to combine the power of single-cell and omics approaches.
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Affiliation(s)
- Mitja N P Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Rudolf O Schlechter
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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21
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22
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Vacher C, Hampe A, Porté AJ, Sauer U, Compant S, Morris CE. The Phyllosphere: Microbial Jungle at the Plant–Climate Interface. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2016. [DOI: 10.1146/annurev-ecolsys-121415-032238] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Arndt Hampe
- BIOGECO, INRA, Univ. Bordeaux, 33610 Cestas, France
| | | | - Ursula Sauer
- Bioresources Unit, Department of Health and Environment, AIT Austrian Institute of Technology GmbH, 3430 Tulln, Austria
| | - Stéphane Compant
- Bioresources Unit, Department of Health and Environment, AIT Austrian Institute of Technology GmbH, 3430 Tulln, Austria
| | - Cindy E. Morris
- INRA, Unité de Recherche de Pathologie Végétale, 84143 Montfavet, France
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