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Barone GD, Zhou Y, Wang H, Xu S, Ma Z, Cernava T, Chen Y. Implications of bacteria‒bacteria interactions within the plant microbiota for plant health and productivity. J Zhejiang Univ Sci B 2024:1-16. [PMID: 38773879 DOI: 10.1631/jzus.b2300914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 02/26/2024] [Indexed: 05/24/2024]
Abstract
Crop production currently relies on the widespread use of agrochemicals to ensure food security. This practice is considered unsustainable, yet has no viable alternative at present. The plant microbiota can fulfil various functions for its host, some of which could be the basis for developing sustainable protection and fertilization strategies for plants without relying on chemicals. To harness such functions, a detailed understanding of plant‒microbe and microbe‒microbe interactions is necessary. Among interactions within the plant microbiota, those between bacteria are the most common ones; they are not only of ecological importance but also essential for maintaining the health and productivity of the host plants. This review focuses on recent literature in this field and highlights various consequences of bacteria‒bacteria interactions under different agricultural settings. In addition, the molecular and genetic backgrounds of bacteria that facilitate such interactions are emphasized. Representative examples of commonly found bacterial metabolites with bioactive properties, as well as their modes of action, are given. Integrating our understanding of various binary interactions into complex models that encompass the entire microbiota will benefit future developments in agriculture and beyond, which could be further facilitated by artificial intelligence-based technologies.
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Affiliation(s)
| | - Yaqi Zhou
- State Key Laboratory of Rice Biology and Breeding; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects; Zhejiang Provincial Key Laboratory of Biology of Crop Pathogens and Insects; Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Hongkai Wang
- State Key Laboratory of Rice Biology and Breeding; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects; Zhejiang Provincial Key Laboratory of Biology of Crop Pathogens and Insects; Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Sunde Xu
- State Key Laboratory of Rice Biology and Breeding; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects; Zhejiang Provincial Key Laboratory of Biology of Crop Pathogens and Insects; Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology and Breeding; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects; Zhejiang Provincial Key Laboratory of Biology of Crop Pathogens and Insects; Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Tomislav Cernava
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, SO17 1BJ Southampton, UK.
| | - Yun Chen
- State Key Laboratory of Rice Biology and Breeding; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects; Zhejiang Provincial Key Laboratory of Biology of Crop Pathogens and Insects; Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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2
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Álvarez-García S, Moumni M, Romanazzi G. Antifungal activity of volatile organic compounds from essential oils against the postharvest pathogens Botrytis cinerea, Monilinia fructicola, Monilinia fructigena, and Monilinia laxa. FRONTIERS IN PLANT SCIENCE 2023; 14:1274770. [PMID: 37860258 PMCID: PMC10582630 DOI: 10.3389/fpls.2023.1274770] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/13/2023] [Indexed: 10/21/2023]
Abstract
Gray mold and brown rot, caused respectively by Botrytis cinerea and Monilinia spp., are fungal diseases responsible for significant losses during the storage of fruit and vegetables. Nowadays, the control of postharvest diseases is shifting towards more sustainable strategies, including the use of plant secondary metabolites. In this study, the antifungal activity of Origanum vulgare, Thymus vulgaris, Thymus serpyllum, Melaleuca alternifolia, Lavandula officinalis, Lavandula hybrida, Citrus bergamia, Rosmarinus officinalis, Cinnamomum zeylanicum essential oils (EOs) in vapor phase was tested in vitro against B. cinerea, Monilinia fructicola, Monilinia fructigena, and Monilinia laxa. For the experiments, a protocol using a volatile organic compounds (VOC) chamber was designed. Results indicate a dose-dependent inhibitory activity of all the tested EOs, with O. vulgare, T. vulgaris, and T. serpyllum being the most active ones, with minimum inhibitory concentrations (MIC) of 22.73, 45.45, and 22.73 µl/L, respectively, against B. cinerea and a range between 5.64 and 22.73 µl/L against the three Monilinia spp. Overall, B. cinerea presented lower sensitivity to vapor-phase EOs than any of the Monilinia strains, except for the C. zeylanicum EO, which consistently showed higher inhibition against B. cinerea. Among the three Monilinia spp., M. fructicola was the least sensitive, while M. fructigena was the most sensitive. The use of VOC chambers proved to be a reliable protocol for the assessment of antimicrobial activities of EOs. These results suggest that the VOC emitted by the tested EOs are effective towards important decay-causing fungi, and that they could be used for the control of gray mold and brown rot in in vivo trials.
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Affiliation(s)
- Samuel Álvarez-García
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
- Plant Physiology Area, Engineering and Agricultural Sciences Department, Universidad de León, León, Spain
| | - Marwa Moumni
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Gianfranco Romanazzi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
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3
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Thomas G, Rusman Q, Morrison WR, Magalhães DM, Dowell JA, Ngumbi E, Osei-Owusu J, Kansman J, Gaffke A, Pagadala Damodaram KJ, Kim SJ, Tabanca N. Deciphering Plant-Insect-Microorganism Signals for Sustainable Crop Production. Biomolecules 2023; 13:997. [PMID: 37371577 DOI: 10.3390/biom13060997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Agricultural crop productivity relies on the application of chemical pesticides to reduce pest and pathogen damage. However, chemical pesticides also pose a range of ecological, environmental and economic penalties. This includes the development of pesticide resistance by insect pests and pathogens, rendering pesticides less effective. Alternative sustainable crop protection tools should therefore be considered. Semiochemicals are signalling molecules produced by organisms, including plants, microbes, and animals, which cause behavioural or developmental changes in receiving organisms. Manipulating semiochemicals could provide a more sustainable approach to the management of insect pests and pathogens across crops. Here, we review the role of semiochemicals in the interaction between plants, insects and microbes, including examples of how they have been applied to agricultural systems. We highlight future research priorities to be considered for semiochemicals to be credible alternatives to the application of chemical pesticides.
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Affiliation(s)
- Gareth Thomas
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Quint Rusman
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008 Zürich, Switzerland
| | - William R Morrison
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Grain and Animal Health Research, 1515 College Ave., Manhattan, KS 66502, USA
| | - Diego M Magalhães
- Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Jordan A Dowell
- Department of Plant Sciences, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
| | - Esther Ngumbi
- Department of Entomology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA
| | - Jonathan Osei-Owusu
- Department of Biological, Physical and Mathematical Sciences, University of Environment and Sustainable Development, Somanya EY0329-2478, Ghana
| | - Jessica Kansman
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Alexander Gaffke
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Medical, Agricultural, and Veterinary Entomology, 6383 Mahan Dr., Tallahassee, FL 32308, USA
| | | | - Seong Jong Kim
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Natural Products Utilization Research Unit, University, MS 38677, USA
| | - Nurhayat Tabanca
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Subtropical Horticulture Research Station, 13601 Old Cutler Rd., Miami, FL 33158, USA
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4
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Grahovac J, Pajčin I, Vlajkov V. Bacillus VOCs in the Context of Biological Control. Antibiotics (Basel) 2023; 12:antibiotics12030581. [PMID: 36978448 PMCID: PMC10044676 DOI: 10.3390/antibiotics12030581] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
A contemporary agricultural production system relying on heavy usage of agrochemicals represents a questionable outlook for sustainable food supply in the future. The visible negative environmental impacts and unforeseen consequences to human and animal health have been requiring a shift towards the novel eco-friendly alternatives for chemical pesticides for a while now. Microbial-based biocontrol agents have shown a promising potential for plant disease management. The bacteria of the genus Bacillus have been among the most exploited microbial active components due to several highly efficient mechanisms of action against plant pathogens, as well as a palette of additional plant-beneficial mechanisms, together with their suitable properties for microbial biopesticide formulations. Among other bioactive metabolites, volatile organic compounds (VOCs) have been investigated for their biocontrol applications, exhibiting the main advantage of long-distance effect without the necessity for direct contact with plants or pathogens. The aim of this study is to give an overview of the state-of-the-art in the field of Bacillus-based VOCs, especially in terms of their antibacterial, antifungal, and nematicidal action as the main segments determining their potential for biocontrol applications in sustainable agriculture.
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Almeida OAC, de Araujo NO, Mulato ATN, Persinoti GF, Sforça ML, Calderan-Rodrigues MJ, Oliveira JVDC. Bacterial volatile organic compounds (VOCs) promote growth and induce metabolic changes in rice. FRONTIERS IN PLANT SCIENCE 2023; 13:1056082. [PMID: 36844905 PMCID: PMC9948655 DOI: 10.3389/fpls.2022.1056082] [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: 09/29/2022] [Accepted: 12/13/2022] [Indexed: 06/18/2023]
Abstract
Plant growth-promoting bacteria (PGPB) represent an eco-friendly alternative to reduce the use of chemical products while increasing the productivity of economically important crops. The emission of small gaseous signaling molecules from PGPB named volatile organic compounds (VOCs) has emerged as a promising biotechnological tool to promote biomass accumulation in model plants (especially Arabidopsis thaliana) and a few crops, such as tomato, lettuce, and cucumber. Rice (Oryza sativa) is the most essential food crop for more than half of the world's population. However, the use of VOCs to improve this crop performance has not yet been investigated. Here, we evaluated the composition and effects of bacterial VOCs on the growth and metabolism of rice. First, we selected bacterial isolates (IAT P4F9 and E.1b) that increased rice dry shoot biomass by up to 83% in co-cultivation assays performed with different durations of time (7 and 12 days). Metabolic profiles of the plants co-cultivated with these isolates and controls (without bacteria and non-promoter bacteria-1003-S-C1) were investigated via 1H nuclear magnetic resonance. The analysis identified metabolites (e.g., amino acids, sugars, and others) with differential abundance between treatments that might play a role in metabolic pathways, such as protein synthesis, signaling, photosynthesis, energy metabolism, and nitrogen assimilation, involved in rice growth promotion. Interestingly, VOCs from IAT P4F9 displayed a more consistent promotion activity and were also able to increase rice dry shoot biomass in vivo. Molecular identification by sequencing the 16S rRNA gene of the isolates IAT P4F9 and E.1b showed a higher identity with Serratia and Achromobacter species, respectively. Lastly, volatilomes of these and two other non-promoter bacteria (1003-S-C1 and Escherichia coli DH5α) were evaluated through headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Compounds belonging to different chemical classes, such as benzenoids, ketones, alcohols, sulfide, alkanes, and pyrazines, were identified. One of these VOCs, nonan-2-one, was validated in vitro as a bioactive compound capable of promoting rice growth. Although further analyses are necessary to properly elucidate the molecular mechanisms, our results suggest that these two bacterial isolates are potential candidates as sources for bioproducts, contributing to a more sustainable agriculture.
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Affiliation(s)
- Octávio Augusto Costa Almeida
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Natália Oliveira de Araujo
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Aline Tieppo Nogueira Mulato
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Gabriela Felix Persinoti
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Maurício Luís Sforça
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | | | - Juliana Velasco de Castro Oliveira
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
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Riu M, Kim MS, Choi SK, Oh SK, Ryu CM. Elicitation of Innate Immunity by a Bacterial Volatile 2-Nonanone at Levels below Detection Limit in Tomato Rhizosphere. Mol Cells 2022; 45:502-511. [PMID: 35791736 PMCID: PMC9260139 DOI: 10.14348/molcells.2022.2009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/24/2022] [Accepted: 02/24/2022] [Indexed: 11/27/2022] Open
Abstract
Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.
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Affiliation(s)
- Myoungjoo Riu
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Applied Biology, College of Agriculture & Life Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Man Su Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering Program, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering Program, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
| | - Sang-Keun Oh
- Department of Applied Biology, College of Agriculture & Life Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Choong-Min Ryu
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering Program, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
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7
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Heenan-Daly D, Coughlan S, Dillane E, Doyle Prestwich B. Volatile Compounds From Bacillus, Serratia, and Pseudomonas Promote Growth and Alter the Transcriptional Landscape of Solanum tuberosum in a Passively Ventilated Growth System. Front Microbiol 2021; 12:628437. [PMID: 34367077 PMCID: PMC8333284 DOI: 10.3389/fmicb.2021.628437] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 06/07/2021] [Indexed: 11/15/2022] Open
Abstract
The interaction of an array of volatile organic compounds (VOCs) termed bacterial volatile compounds (BVCs) with plants is now a major area of study under the umbrella of plant-microbe interactions. Many growth systems have been developed to determine the nature of these interactions in vitro. However, each of these systems have their benefits and drawbacks with respect to one another and can greatly influence the end-point interpretation of the BVC effect on plant physiology. To address the need for novel growth systems in BVC-plant interactions, our study investigated the use of a passively ventilated growth system, made possible via Microbox® growth chambers, to determine the effect of BVCs emitted by six bacterial isolates from the genera Bacillus, Serratia, and Pseudomonas. Solid-phase microextraction GC/MS was utilized to determine the BVC profile of each bacterial isolate when cultured in three different growth media each with varying carbon content. 66 BVCs were identified in total, with alcohols and alkanes being the most abundant. When cultured in tryptic soy broth, all six isolates were capable of producing 2,5-dimethylpyrazine, however BVC emission associated with this media were deemed to have negative effects on plant growth. The two remaining media types, namely Methyl Red-Voges Proskeur (MR-VP) and Murashige and Skoog (M + S), were selected for bacterial growth in co-cultivation experiments with Solanum tuberosum L. cv. ‘Golden Wonder.’ The BVC emissions of Bacillus and Serratia isolates cultured on MR-VP induced alterations in the transcriptional landscape of potato across all treatments with 956 significantly differentially expressed genes. This study has yielded interesting results which indicate that BVCs may not always broadly upregulate expression of defense genes and this may be due to choice of plant-bacteria co-cultivation apparatus, bacterial growth media and/or strain, or likely, a complex interaction between these factors. The multifactorial complexities of observed effects of BVCs on target organisms, while intensely studied in recent years, need to be further elucidated before the translation of lab to open-field applications can be fully realized.
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Affiliation(s)
- Darren Heenan-Daly
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Simone Coughlan
- School of Mathematics, Statistics and Applied Mathematics, National University of Ireland, Galway, Ireland
| | - Eileen Dillane
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Barbara Doyle Prestwich
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
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8
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C4 Bacterial Volatiles Improve Plant Health. Pathogens 2021; 10:pathogens10060682. [PMID: 34072921 PMCID: PMC8227687 DOI: 10.3390/pathogens10060682] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/10/2021] [Accepted: 05/24/2021] [Indexed: 02/04/2023] Open
Abstract
Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.
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Fincheira P, Quiroz A, Tortella G, Diez MC, Rubilar O. Current advances in plant-microbe communication via volatile organic compounds as an innovative strategy to improve plant growth. Microbiol Res 2021; 247:126726. [PMID: 33640574 DOI: 10.1016/j.micres.2021.126726] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/25/2021] [Accepted: 02/10/2021] [Indexed: 12/18/2022]
Abstract
Volatile organic compounds (VOCs) emitted by microorganisms have demonstrated an important role to improve growth and tolerance against abiotic stress on plants. Most studies have used Arabidopsis thaliana as a model plant, extending to other plants of commercial interest in the last years. Interestingly, the microbial VOCs are characterized by its biodegradable structure, quick action, absence of toxic substances, and acts at lower concentration to regulate plant physiological changes. These compounds modulate plant physiological processes such as phytohormone pathways, photosynthesis, nutrient acquisition, and metabolisms. Besides, the regulation of gene expression associated with cell components, biological processes, and molecular function are triggered by microbial VOCs. Otherwise, few studies have reported the important role of VOCs for confer plant tolerance to abiotic stress, such as drought and salinity. Although VOCs have shown an efficient action to enhance the plant growth under controlled conditions, there are still great challenges for their greenhouse or field application. Therefore, in this review, we summarize the current knowledge about the technical procedures, study cases, and physiological mechanisms triggered by microbial VOCs to finally discuss the challenges of its application in agriculture.
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Affiliation(s)
- Paola Fincheira
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile.
| | - Andrés Quiroz
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile; Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile
| | - Gonzalo Tortella
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile; Departamento de Ingeniería Química, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile
| | - María Cristina Diez
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile; Departamento de Ingeniería Química, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile
| | - Olga Rubilar
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile; Departamento de Ingeniería Química, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile
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Thomas G, Withall D, Birkett M. Harnessing microbial volatiles to replace pesticides and fertilizers. Microb Biotechnol 2020; 13:1366-1376. [PMID: 32767638 PMCID: PMC7415372 DOI: 10.1111/1751-7915.13645] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/17/2020] [Accepted: 07/19/2020] [Indexed: 12/13/2022] Open
Abstract
Global agricultural systems are under increasing pressure to deliver sufficient, healthy food for a growing population. Seasonal inputs, including synthetic pesticides and fertilizers, are applied to crops to reduce losses by pathogens, and enhance crop biomass, although their production and application can also incur several economic and environmental penalties. New solutions are therefore urgently required to enhance crop yield whilst reducing dependence on these seasonal inputs. Volatile Organic Compounds (VOCs) produced by soil microorganisms may provide alternative, sustainable solutions, due to their ability to inhibit plant pathogens, induce plant resistance against pathogens and enhance plant growth promotion. This review will highlight recent advances in our understanding of the biological activities of microbial VOCs (mVOCs), providing perspectives on research required to develop them into viable alternatives to current unsustainable seasonal inputs. This can identify potential new avenues for mVOC research and stimulate discussion across the academic community and agri-business sector.
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Affiliation(s)
- Gareth Thomas
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
- School of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - David Withall
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Michael Birkett
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
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11
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Garbeva P, Weisskopf L. Airborne medicine: bacterial volatiles and their influence on plant health. THE NEW PHYTOLOGIST 2020; 226:32-43. [PMID: 31651035 DOI: 10.1111/nph.16282] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/09/2019] [Indexed: 05/21/2023]
Abstract
Like most other eukaryotes, plants do not live alone but in close association with a diverse microflora. These plant-associated microbes contribute to plant health in many different ways, ranging from modulation of hormonal pathways to direct antibiosis of plant pathogens. Over the last 15 yr, the importance of volatile organic compounds as mediators of mutualistic interactions between plant-associated bacteria and their hosts has become evident. This review summarizes current knowledge concerning bacterial volatile-mediated plant protection against abiotic and biotic stresses. It then discusses the translational potential of such metabolites or of their emitters for sustainable crop protection, the possible ways to harness this potential, and the major challenges still preventing us from doing so. Finally, the review concludes with highlighting the most pressing scientific gaps that need to be filled in order to enable a better understanding of: the molecular mechanisms underlying the biosynthesis of bacterial volatiles; the complex regulation of bacterial volatile emission in natural communities; the perception of bacterial volatiles by plants; and the modes of actions of bacterial volatiles on their host.
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Affiliation(s)
- Paolina Garbeva
- Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, the Netherlands
| | - Laure Weisskopf
- Department of Biology, University of Fribourg, Chemin du musée 10, CH-1700, Fribourg, Switzerland
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Pršić J, Ongena M. Elicitors of Plant Immunity Triggered by Beneficial Bacteria. FRONTIERS IN PLANT SCIENCE 2020; 11:594530. [PMID: 33304371 PMCID: PMC7693457 DOI: 10.3389/fpls.2020.594530] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/07/2020] [Indexed: 05/19/2023]
Abstract
The molecular basis of plant immunity triggered by microbial pathogens is being well-characterized as a complex sequential process leading to the activation of defense responses at the infection site, but which may also be systemically expressed in all organs, a phenomenon also known as systemic acquired resistance (SAR). Some plant-associated and beneficial bacteria are also able to stimulate their host to mount defenses against pathogen ingress via the phenotypically similar, induced systemic resistance phenomenon. Induced systemic resistance resembles SAR considering its mechanistic principle as it successively involves recognition at the plant cell surface, stimulation of early cellular immune-related events, systemic signaling via a fine-tuned hormonal cross-talk and activation of defense mechanisms. It thus represents an indirect but efficient mechanism by which beneficial bacteria with biocontrol potential improve the capacity of plants to restrict pathogen invasion. However, according to our current vision, induced systemic resistance is specific considering some molecular aspects underpinning these different steps. Here we overview the chemical diversity of compounds that have been identified as induced systemic resistance elicitors and thereby illustrating the diversity of plants species that are responsive as well as the range of pathogens that can be controlled via this phenomenon. We also point out the need for further investigations allowing better understanding how these elicitors are sensed by the host and the diversity and nature of the stimulated defense mechanisms.
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