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Ding Y, Gardiner DM, Kazan K. Transcriptome analysis reveals infection strategies employed by Fusarium graminearum as a root pathogen. Microbiol Res 2021; 256:126951. [PMID: 34972022 DOI: 10.1016/j.micres.2021.126951] [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: 03/09/2021] [Revised: 07/27/2021] [Accepted: 10/15/2021] [Indexed: 10/19/2022]
Abstract
The fungal pathogen Fusarium graminearum (Fg) infects both heads and roots of cereal crops causing several economically important diseases such as head blight, seedling blight, crown rot and root rot. Trichothecene mycotoxins such as deoxynivalenol (DON), a well-known virulence factor, produced by Fg during disease development is also an important health concern. Although how Fg infects above-ground tissues is relatively well studied, very little is known about molecular processes employed by the pathogen during below-ground infection. Also unknown is the role of DON during root infection. In the present study, we analyzed the transcriptome of Fg during root infection of the model cereal Brachypodium distachyon (Bd). We also compared our Fg transcriptome data obtained during Bd root infection with those reported during wheat head infection. These analyses suggested that both shared and unique infection strategies were employed by the pathogen during colonization of different host tissues. Several metabolite biosynthesis genes induced in Fg during root infection could be linked to phytohormone production, implying that the pathogen likely interferes with root specific defenses. In addition, to understand the role of DON in Fg root infection, we analyzed the transcriptome of the DON deficient Tri5 mutant. These analyses showed that the absence of DON had a significant effect on fungal transcriptional responses. Although DON was produced in infected roots, this mycotoxin did not act as a Fg virulence factor during root infection. Our results reveal new mechanistic insights into the below-ground strategies employed by Fg that may benefit the development of new genetic tools to combat this important cereal pathogen.
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Affiliation(s)
- Yi Ding
- The Plant Breeding Institute, School of Life & Environmental Sciences, Faculty of Science, The University of Sydney, Cobbitty, 2570, New South Wales, Australia; Agriculture and Food, Commonwealth Scientific and Industrial Research Organization, 306 Carmody Road, St Lucia, 4067, Queensland, Australia.
| | - Donald M Gardiner
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Brisbane, St Lucia, 4067, Queensland, Australia; Agriculture and Food, Commonwealth Scientific and Industrial Research Organization, 306 Carmody Road, St Lucia, 4067, Queensland, Australia
| | - Kemal Kazan
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Brisbane, St Lucia, 4067, Queensland, Australia; Agriculture and Food, Commonwealth Scientific and Industrial Research Organization, 306 Carmody Road, St Lucia, 4067, Queensland, Australia.
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Karlsson I, Persson P, Friberg H. Fusarium Head Blight From a Microbiome Perspective. Front Microbiol 2021; 12:628373. [PMID: 33732223 PMCID: PMC7956947 DOI: 10.3389/fmicb.2021.628373] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/08/2021] [Indexed: 11/25/2022] Open
Abstract
The fungal genus Fusarium causes several diseases in cereals, including Fusarium head blight (FHB). A number of Fusarium species are involved in disease development and mycotoxin contamination. Lately, the importance of interactions between plant pathogens and the plant microbiome has been increasingly recognized. In this review, we address the significance of the cereal microbiome for the development of Fusarium-related diseases. Fusarium fungi may interact with the host microbiome at multiple stages during their life cycles and in different plant organs including roots, stems, leaves, heads, and crop residues. There are interactions between Fusarium and other fungi and bacteria as well as among Fusarium species. Recent studies have provided a map of the cereal microbiome and revealed how different biotic and abiotic factors drive microbiome assembly. This review synthesizes the current understanding of the cereal microbiome and the implications for Fusarium infection, FHB development, disease control, and mycotoxin contamination. Although annual and regional variations in predominant species are significant, much research has focused on Fusarium graminearum. Surveying the total Fusarium community in environmental samples is now facilitated with novel metabarcoding methods. Further, infection with multiple Fusarium species has been shown to affect disease severity and mycotoxin contamination. A better mechanistic understanding of such multiple infections is necessary to be able to predict the outcome in terms of disease development and mycotoxin production. The knowledge on the composition of the cereal microbiome under different environmental and agricultural conditions is growing. Future studies are needed to clearly link microbiome structure to Fusarium suppression in order to develop novel disease management strategies for example based on conservation biological control approaches.
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Affiliation(s)
- Ida Karlsson
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Paula Persson
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Hanna Friberg
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Zhang J, Chen J, Hu L, Jia R, Ma Q, Tang J, Wang Y. Antagonistic action of Streptomyces pratensis S10 on Fusarium graminearum and its complete genome sequence. Environ Microbiol 2020; 23:1925-1940. [PMID: 33073508 DOI: 10.1111/1462-2920.15282] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/15/2020] [Indexed: 12/19/2022]
Abstract
Wheat scab, mainly caused by Fusarium graminearum, can decrease wheat yield and grain quality. Chemical pesticides are currently the main control method but have an inevitable negative consequence on the environment and in food safety. This research studies a promising substitute, Streptomyces pratensis S10, which was isolated from tomato leaf mould and shows a significant inhibition effect on F. graminearum based on antagonism assays. The biocontrol mechanism is studied by enhanced green fluorescent protein labelling, quantitative real-time PCR, the Doskochilova 8 solvents system test and complete genome sequencing. Strain S10 can colonize in the wheat root, control wheat scab and decrease deoxynivalenol (DON) content. The control effects in vitro, planta and the plot experiments were 92.86%, 68.67% and 40.87% to 86.62%, respectively. S10 decreased DON content by inhibiting the mycelium growth and DON synthesis gene expression. The active substances of the S10 secondary metabolites had a high-temperature resistance and 29 putative biosynthetic gene clusters in its genome. The S10 control mechanism is multivariate, which shows potential in controlling wheat scab.
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Affiliation(s)
- Jing Zhang
- College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Jing Chen
- College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Lifang Hu
- College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Ruimin Jia
- College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Qing Ma
- College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Jiangjiang Tang
- Shaanxi Key Laboratory of Natural Products and Chemical Biology, College of Chemistry and Pharmacy, Northwest A&F University, Xianyang, China
| | - Yang Wang
- College of Plant Protection, Northwest A&F University, Xianyang, China
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Legrand F, Chen W, Cobo-Díaz JF, Picot A, Floch GL. Co-occurrence analysis reveal that biotic and abiotic factors influence soil fungistasis against Fusarium graminearum. FEMS Microbiol Ecol 2020; 95:5475120. [PMID: 30998232 DOI: 10.1093/femsec/fiz056] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 04/16/2019] [Indexed: 02/05/2023] Open
Abstract
The current study determined the levels of soil fungistasis against a soil-borne pathogen inoculum, Fusarium graminearum (Fg, a major causal agent of Fusarium Head Blight (FHB)), in 31 wheat fields by quantifying Fg growth after a 15-day incubation period using qPCR in autoclaved versus non-autoclaved soils. The results were used to define the six most Fg-resistant and the six most Fg-conducive soils. By using a metabarcoding approach, the diversity of the bacterial communities was significantly higher in Fg-resistant soils than in Fg-conducive soils. Microbial taxa potentially contributing to Fg-fungistasis of soil were selected if they were significantly more prevalent and/or abundant in Fg-resistant soils than in Fg-conducive soils. Some of these candidate indicators, e.g. Pseudomonas spp. and Bacillus spp., have been reported previously as effective biocontrol agents against plant pathogens. Correlation-based network analysis further showed that the members of the bacterial communities in Fg-resistant soils were more connected than in Fg-conducive soils. Moreover, network modules was found significantly correlated with certain edaphic abiotics factors (such as the soil manganese and nitrogen content) and Fg-fungistasis. Such observations may suggest and emphasize, although conceptual, the importance of synergistic rather than individual effects of network members, and the nutrient use efficiency in contributing to Fg-resistance of soils in wheat fields in France.
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Affiliation(s)
- Fabienne Legrand
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France.,Lallemand SAS, 4 route de Beaupuy, 31180 Castelmaurou, France
| | - Wen Chen
- Ottawa Research & Development Centre, Science & Technology Branch, Agriculture and Agri-Food Canada, 960 Carling Ave. Ottawa, ON, K1A 0C6, Canada
| | - José Francisco Cobo-Díaz
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Adeline Picot
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Gaétan Le Floch
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
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Schiro G, Müller T, Verch G, Sommerfeld T, Mauch T, Koch M, Grimm V, Müller MEH. The distribution of mycotoxins in a heterogeneous wheat field in relation to microclimate, fungal and bacterial abundance. J Appl Microbiol 2018; 126:177-190. [PMID: 30216614 DOI: 10.1111/jam.14104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/25/2018] [Accepted: 08/29/2018] [Indexed: 12/24/2022]
Abstract
AIM To observe the variation in accumulation of Fusarium and Alternaria mycotoxins across a topographically heterogeneous field and tested biotic (fungal and bacterial abundance) and abiotic (microclimate) parameters as explanatory variables. METHODS AND RESULTS We selected a wheat field characterized by a diversified topography, to be responsible for variations in productivity and in canopy-driven microclimate. Fusarium and Alternaria mycotoxins where quantified in wheat ears at three sampling dates between flowering and harvest at 40 points. Tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), deoxynivalenol (DON), zearalenone (ZEN) and deoxynivalenol-3-Glucoside (DON.3G) were quantified. In canopy temperature, air and soil humidity were recorded for each point with data-loggers. Fusarium spp. as trichothecene producers, Alternaria spp. and fungal abundances were assessed using qPCR. Pseudomonas fluorescens bacteria were quantified with a culture based method. We only found DON, DON.3G, TeA and TEN to be ubiquitous across the whole field, while AME, AOH and ZEN were only occasionally detected. Fusarium was more abundant in spots with high soil humidity, while Alternaria in warmer and drier spots. Mycotoxins correlated differently to the observed explanatory variables: positive correlations between DON accumulation, tri 5 gene and Fusarium abundance were clearly detected. The correlations among the others observed variables, such as microclimatic conditions, varied among the sampling dates. The results of statistical model identification do not exclude that species coexistence could influence mycotoxin production. CONCLUSIONS Fusarium and Alternaria mycotoxins accumulation varies heavily across the field and the sampling dates, providing the realism of landscape-scale studies. Mycotoxin concentrations appear to be partially explained by biotic and abiotic variables. SIGNIFICANCE AND IMPACT OF THE STUDY We provide a useful experimental design and useful data for understanding the dynamics of mycotoxin biosynthesis in wheat.
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Affiliation(s)
- G Schiro
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - T Müller
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - G Verch
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - T Sommerfeld
- Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - T Mauch
- Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - M Koch
- Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - V Grimm
- Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - M E H Müller
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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Palazzini J, Roncallo P, Cantoro R, Chiotta M, Yerkovich N, Palacios S, Echenique V, Torres A, Ramírez M, Karlovsky P, Chulze S. Biocontrol of Fusarium graminearum sensu stricto, Reduction of Deoxynivalenol Accumulation and Phytohormone Induction by Two Selected Antagonists. Toxins (Basel) 2018; 10:E88. [PMID: 29461480 PMCID: PMC5848189 DOI: 10.3390/toxins10020088] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/06/2018] [Accepted: 02/14/2018] [Indexed: 11/16/2022] Open
Abstract
Fusarium head blight (FHB) is a devastating disease that causes extensive yield and quality losses to wheat and other small cereal grains worldwide. Species within the Fusarium graminearum complex are the main pathogens associated with the disease, F. graminearum sensu stricto being the main pathogen in Argentina. Biocontrol can be used as part of an integrated pest management strategy. Phytohormones play a key role in the plant defense system and their production can be induced by antagonistic microorganisms. The aims of this study were to evaluate the effect of the inoculation of Bacillus velezensis RC 218, F. graminearum and their co-inoculation on the production of salicylic acid (SA) and jasmonic acid (JA) in wheat spikes at different periods of time under greenhouse conditions, and to evaluate the effect of B. velezensis RC 218 and Streptomyces albidoflavus RC 87B on FHB disease incidence, severity and deoxynivalenol accumulation on Triticum turgidum L. var. durum under field conditions. Under greenhouse conditions the production of JA was induced after F. graminearum inoculation at 48 and 72 h, but JA levels were reduced in the co-inoculated treatments. No differences in JA or SA levels were observed between the B. velezensis treatment and the water control. In the spikes inoculated with F. graminearum, SA production was induced early (12 h), as it was shown for initial FHB basal resistance, while JA was induced at a later stage (48 h), revealing different defense strategies at different stages of infection by the hemibiotrophic pathogen F. graminearum. Both B. velezensis RC 218 and S. albidoflavus RC 87B effectively reduced FHB incidence (up to 30%), severity (up to 25%) and deoxynivalenol accumulation (up to 51%) on durum wheat under field conditions.
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Affiliation(s)
- Juan Palazzini
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Pablo Roncallo
- CERZOS-CONICET, Department of Agronomy, UNS-CCT CONICET Bahía Blanca, Camino de la Carrindanga Km 7, Bahía Blanca 8000, Argentina.
| | - Renata Cantoro
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Maria Chiotta
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Nadia Yerkovich
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Sofia Palacios
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Viviana Echenique
- CERZOS-CONICET, Department of Agronomy, UNS-CCT CONICET Bahía Blanca, Camino de la Carrindanga Km 7, Bahía Blanca 8000, Argentina.
| | - Adriana Torres
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - María Ramírez
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
| | - Petr Karlovsky
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University, Grisebachstrasse 6, 37077 Goettingen, Germany.
| | - Sofia Chulze
- Department of Microbiology and Immunology, Faculty of Exact Sciences, National University of Río Cuarto, Route 36 Km 601, Río Cuarto, Córdoba 5800, Argentina.
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Rais A, Jabeen Z, Shair F, Hafeez FY, Hassan MN. Bacillus spp., a bio-control agent enhances the activity of antioxidant defense enzymes in rice against Pyricularia oryzae. PLoS One 2017; 12:e0187412. [PMID: 29161274 PMCID: PMC5697883 DOI: 10.1371/journal.pone.0187412] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/19/2017] [Indexed: 12/18/2022] Open
Abstract
Plant growth promoting rhizobacteria (PGPR) are found to control the plant diseases by adopting various mechanisms. Induced systemic resistance (ISR) is an important defensive strategy manifested by plants against numerous pathogens especially infecting at aerial parts. Rhizobacteria elicit ISR by inducing different pathways in plants through production of various metabolites. In the present study, potential of Bacillus spp. KFP-5, KFP-7, KFP-17 was assessed to induce antioxidant enzymes against Pyricularia oryzae infection in rice. The antagonistic Bacillus spp. significantly induced antioxidant defense enzymes i-e superoxide dismutase (1.7–1.9-fold), peroxidase (3.5–4.1-fold), polyphenol oxidase (3.0–3.8-fold), phenylalanine ammonia-lyase (3.9–4.4-fold), in rice leaves and roots under hydroponic and soil conditions respectively. Furthermore, the antagonistic Bacillus spp significantly colonized the rice plants (2.0E+00–9.1E+08) and secreted multiple biocontrol determinants like protease (1.1–5.5 U/mg of soil or U/mL of hydroponic solution), glucanase, (1.0–1.3 U/mg of soil or U/mL of hydroponic solution), siderophores (6.5–42.8 μg/mL or mg) in the rhizosphere of different rice varieties. The results showed that treatment with Bacillus spp. enhanced the antioxidant defense activities in infected rice, thus alleviating P. oryzae induced oxidative damage and suppressing blast disease incidence.
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Affiliation(s)
- Afroz Rais
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Zahra Jabeen
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Faluk Shair
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Fauzia Yusuf Hafeez
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Muhammad Nadeem Hassan
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
- * E-mail:
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Wang Q, Vera Buxa S, Furch A, Friedt W, Gottwald S. Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1288-303. [PMID: 26325125 DOI: 10.1094/mpmi-07-15-0144-r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a 'new' aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.
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Affiliation(s)
- Qing Wang
- 1 Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Stefanie Vera Buxa
- 2 Institute of Phytopathology and Applied Zoology, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Alexandra Furch
- 3 Friedrich-Schiller University Jena, Institute of General Botany and Plant Physiology, Dornburger Str. 159, 07743 Jena, Germany
| | - Wolfgang Friedt
- 1 Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Sven Gottwald
- 1 Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
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Hu W, Gao Q, Hamada MS, Dawood DH, Zheng J, Chen Y, Ma Z. Potential of Pseudomonas chlororaphis subsp. aurantiaca Strain Pcho10 as a Biocontrol Agent Against Fusarium graminearum. PHYTOPATHOLOGY 2014; 104:1289-1297. [PMID: 24941327 DOI: 10.1094/phyto-02-14-0049-r] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
To develop an effective biocontrol strategy for management of Fusarium head blight on wheat caused by Fusarium graminearum, the bacterial biocontrol agent Pcho10 was selected from more than 1,476 wheat-head-associated bacterial strains according to its antagonistic activity in vitro. This strain was subsequently characterized as Pseudomonas chlororaphis subsp. aurantiaca based on 16S ribosomal DNA sequence analysis, assays of the BIOLOG microbial identification system, and unique pigment production. The major antifungal metabolite produced by Pcho10 was further identified as phenazine-1-carboxamide (PCN) on the basis of nuclear magnetic resonance data. The core PCN biosynthesis gene cluster in Pcho10 was cloned and sequenced. PCN showed strong inhibitory activity against F. graminearum conidial germination, mycelial growth, and deoxynivalenol production. Tests both under growth chamber conditions and in field trials showed that Pcho10 well colonized on the wheat head and effectively controlled the disease caused by F. graminearum. Results of this study indicate that P. chlororaphis subsp. aurantiaca Pcho10 has high potential to be developed as a biocontrol agent against F. graminearum. To our knowledge, this is the first report of the use of P. chlororaphis for the management of Fusarium head blight.
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Ye J, Guo Y, Zhang D, Zhang N, Wang C, Xu M. Cytological and molecular characterization of quantitative trait locus qRfg1, which confers resistance to gibberella stalk rot in maize. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1417-28. [PMID: 23902264 DOI: 10.1094/mpmi-06-13-0161-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Tremendous progress has been made recently in understanding plant response to Fusarium graminearum infection. Here, the cytological aspect and molecular mechanism of maize defense to F. graminearum infection were characterized using a pair of near-isogenic lines (NIL), the resistant and the susceptible NIL. F. graminearum primarily penetrated the maize root tip and no penetration structure was found. The fungal biomass within the root correlated well with root-disease severity. Following inoculation, R-NIL and S-NIL plants significantly differed in percentage of diseased primary roots. In R-NIL roots, a fraction of exodermal cells collapsed to form cavities, and hyphae were confined to the outer exodermal cells. However, most exodermal cells shrank and turned brown, and fungi colonized the entire S-NIL root. In the R-NIL roots, the exodermal cells exhibited plasmolysis and atropous hyphal growth whereas, in the exodermal cells of the S-NIL roots, severe cellular degradation and membrane-coated, lushly grown hyphae were found. Transcriptome sequencing revealed comprehensive transcription reprogramming, reinforcement of a complex defense network, to enhance the systemic and basal resistance. This study reports a detailed microscopic analysis of F. graminearum infection on maize root, and provides insights into the molecular mechanisms underlying maize resistance to the pathogen.
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Mascher F, Hase C, Bouffaud ML, Défago G, Moënne-Loccoz Y. Cell culturability of Pseudomonas protegens CHA0 depends on soil pH. FEMS Microbiol Ecol 2013; 87:441-50. [PMID: 24224494 DOI: 10.1111/1574-6941.12234] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/30/2013] [Accepted: 09/30/2013] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas inoculants may lose colony-forming ability in soil, but soil properties involved are poorly documented. Here, we tested the hypothesis that soil acidity could reduce persistence and cell culturability of Pseudomonas protegens CHA0. At 1 week in vitro, strain CHA0 was found as culturable cells at pH 7, whereas most cells at pH 4 and all cells at pH 3 were noncultured. In 21 natural soils of contrasted pH, cell culturability loss of P. protegens CHA0 took place in all six very acidic soils (pH < 5.0) and in three of five acidic soils (5.0 < pH < 6.5), whereas it was negligible in the neutral and alkaline soils at 2 weeks and 2 months. No correlation was found between total cell counts of P. protegens CHA0 and soil composition data, whereas colony counts of the strain correlated with soil pH. Maintenance of cell culturability in soils coincided with a reduction in inoculant cell size. Some of the noncultured CHA0 cells were nutrient responsive in Kogure's viability test, both in vitro and in soil. Thus, this shows for the first time that the sole intrinsic soil composition factor triggering cell culturability loss in P. protegens CHA0 is soil acidity.
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Affiliation(s)
- Fabio Mascher
- Plant Pathology, Institute of Integrative Biology, Swiss Federal Institute of Technology, Zürich, Switzerland; Agroscope Changins-Wädenswil research station ACW, Nyon, Switzerland
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Tan S, Dong Y, Liao H, Huang J, Song S, Xu Y, Shen Q. Antagonistic bacterium Bacillus amyloliquefaciens induces resistance and controls the bacterial wilt of tomato. PEST MANAGEMENT SCIENCE 2013; 69:1245-1252. [PMID: 23519834 DOI: 10.1002/ps.3491] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 11/16/2012] [Accepted: 01/21/2013] [Indexed: 06/01/2023]
Abstract
BACKGROUND Bacterial wilt caused by Ralstonia solanacearum (RS) is a serious threat for agricultural production. In this study, Bacillus amyloliquefaciens strains CM-2 and T-5 antagonistic to RS were used to create bioorganic fertilisers to control tomato wilt under greenhouse conditions. The possible mechanism of resistance inducement by the antagonistic bacteria was also evaluated. RESULTS The application of bioorganic fertilisers significantly reduced incidences of tomato wilt (by 63-74%), promoted plant growth and significantly reduced the RS populations in rhizosphere compared with the control. Both strains CM-2 and T-5 applied with bioorganic fertilisers survived well in the tomato rhizosphere. Tomato seedlings treated with cell suspension of T-5 followed by challenge inoculation with RS increased the activities of polyphenol oxidase, phenylalanine ammonia lyase and peroxidase compared with the untreated control. Furthermore, the expressions of the marker genes responsible for synthesis of phytohormones salicylic acid, ethylene and jasmonic acid in seedlings treated with T-5 in response to inoculated pathogen were significantly higher. CONCLUSIONS This study suggests that strains CM-2 and T-5 containing bioorganic fertilisers effectively control tomato wilt. Increased enzyme activities and expression of defence genes in plants indicated that the antagonistic bacteria induced plant resistance, which was the potential biocontrol mechanism of tomato wilt.
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Affiliation(s)
- Shiyong Tan
- Jiangsu Provincial Key Lab of Organic Solid Waste Utilisation, Nanjing Agricultural University, Nanjing, China
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Müller MS, Scheu S, Jousset A. Protozoa Drive the Dynamics of Culturable Biocontrol Bacterial Communities. PLoS One 2013; 8:e66200. [PMID: 23840423 PMCID: PMC3694078 DOI: 10.1371/journal.pone.0066200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 05/05/2013] [Indexed: 11/18/2022] Open
Abstract
Some soil bacteria protect plants against soil-borne diseases by producing toxic secondary metabolites. Such beneficial biocontrol bacteria can be used in agricultural systems as alternative to agrochemicals. The broad spectrum toxins responsible for plant protection also inhibit predation by protozoa and nematodes, the main consumers of bacteria in soil. Therefore, predation pressure may favour biocontrol bacteria and contribute to plant health. We analyzed the effect of Acanthamoeba castellanii on semi-natural soil bacterial communities in a microcosm experiment. We determined the frequency of culturable bacteria carrying genes responsible for the production of the antifungal compounds 2,4-diacetylphloroglucinol (DAPG), pyrrolnitrin (PRN) and hydrogen cyanide (HCN) in presence and absence of A. castellanii. We then measured if amoebae affected soil suppressiveness in a bioassay with sugar beet seedlings confronted to the fungal pathogen Rhizoctonia solani. Amoebae increased the frequency of both DAPG and HCN positive bacteria in later plant growth phases (2 and 3 weeks), as well as the average number of biocontrol genes per bacterium. The abundance of DAPG positive bacteria correlated with disease suppression, suggesting that their promotion by amoebae may enhance soil health. However, the net effect of amoebae on soil suppressiveness was neutral to slightly negative, possibly because amoebae slow down the establishment of biocontrol bacteria on the recently emerged seedlings used in the assay. The results indicate that microfaunal predators foster biocontrol bacterial communities. Understanding interactions between biocontrol bacteria and their predators may thus help developing environmentally friendly management practices of agricultural systems.
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Affiliation(s)
- Maren Stella Müller
- Georg August University Göttingen, J. F. Blumenbach Institute of Zoology and Anthropology, Göttingen, Germany
| | - Stefan Scheu
- Georg August University Göttingen, J. F. Blumenbach Institute of Zoology and Anthropology, Göttingen, Germany
| | - Alexandre Jousset
- Georg August University Göttingen, J. F. Blumenbach Institute of Zoology and Anthropology, Göttingen, Germany
- * E-mail:
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Balmer D, Planchamp C, Mauch-Mani B. On the move: induced resistance in monocots. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:1249-61. [PMID: 23028020 DOI: 10.1093/jxb/ers248] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Although plants possess an arsenal of constitutive defences such as structural barriers and preformed antimicrobial defences, many attackers are able to overcome the pre-existing defence layers. In response, a range of inducible plant defences is set up to battle these pathogens. These mechanisms, commonly integrated as induced resistance (IR), control pathogens and pests by the activation of specific defence pathways. IR mechanisms have been extensively studied in the Dicotyledoneae, whereas knowledge of IR in monocotyledonous plants, including the globally important graminaceous crop plants, is elusive. Considering the potential of IR for sustainable agriculture and the recent advances in monocot genomics and biotechnology, IR in monocots is an emerging research field. In the following, current facts and trends concerning basal immunity, and systemic acquired/induced systemic resistance in the defence of monocots against pathogens and herbivores will be summarized.
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Affiliation(s)
- Dirk Balmer
- Laboratory of Molecular and Cell Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
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Overexpression of wheat lipid transfer protein gene TaLTP5 increases resistances to Cochliobolus sativus and Fusarium graminearum in transgenic wheat. Funct Integr Genomics 2012; 12:481-8. [DOI: 10.1007/s10142-012-0286-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/11/2012] [Accepted: 05/28/2012] [Indexed: 10/28/2022]
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Kazan K, Gardiner DM, Manners JM. On the trail of a cereal killer: recent advances in Fusarium graminearum pathogenomics and host resistance. MOLECULAR PLANT PATHOLOGY 2012; 13:399-413. [PMID: 22098555 PMCID: PMC6638652 DOI: 10.1111/j.1364-3703.2011.00762.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The ascomycete fungal pathogen Fusarium graminearum (sexual stage: Gibberella zeae) causes the devastating head blight or scab disease on wheat and barley, and cob or ear rot disease on maize. Fusarium graminearum infection causes significant crop and quality losses. In addition to roles as virulence factors during pathogenesis, trichothecene mycotoxins (e.g. deoxynivalenol) produced by this pathogen constitute a significant threat to human and animal health if consumed in respective food or feed products. In the last few years, significant progress has been made towards a better understanding of the processes involved in F. graminearum pathogenesis, toxin biosynthesis and host resistance mechanisms through the use of high-throughput genomic and phenomic technologies. In this article, we briefly review these new advances and also discuss how future research can contribute to the development of sustainable plant protection strategies against this important plant pathogen.
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Affiliation(s)
- Kemal Kazan
- CSIRO Plant Industry, Queensland Bioscience Precinct, St Lucia, Brisbane, Qld 4067, Australia.
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