Role of Trichoderma spp. as a Biocontrol Agent of Fungal Plant Pathogens

2017 ◽  
pp. 497-506 ◽  
Author(s):  
Manish Kumar ◽  
Shabbir Ashraf
Keyword(s):  
Plant Pathogens ◽  
Biocontrol Agent ◽  
Trichoderma Spp ◽  
Fungal Plant Pathogens

scholarly journals Role of Lipid Composition and Lipid Peroxidation in the Sensitivity of Fungal Plant Pathogens to Aluminum Chloride and Sodium Metabisulfite

2007 ◽  
Vol 73 (9) ◽  
pp. 2820-2824 ◽  
Author(s):  
Tyler J. Avis ◽  
Mélanie Michaud ◽  
Russell J. Tweddell
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acid ◽  
Aluminum Chloride ◽  
Plant Pathogens ◽  
Membrane Lipids ◽  
Membrane Integrity ◽  
Sodium Metabisulfite ◽  
Fatty Acid Unsaturation ◽  
Fungal Plant Pathogens

ABSTRACT Aluminum chloride and sodium metabisulfite have shown high efficacy at low doses in controlling postharvest pathogens on potato tubers. Direct effects of these two salts included the loss of cell membrane integrity in exposed pathogens. In this work, four fungal potato pathogens were studied in order to elucidate the role of membrane lipids and lipid peroxidation in the relative sensitivity of microorganisms exposed to these salts. Inhibition of mycelial growth in these fungi varied considerably and revealed sensitivity groups within the tested fungi. Analysis of fatty acids in these fungi demonstrated that sensitivity was related to high intrinsic fatty acid unsaturation. When exposed to the antifungal salts, sensitive fungi demonstrated a loss of fatty acid unsaturation, which was accompanied by an elevation in malondialdehyde content (a biochemical marker of lipid peroxidation). Our data suggest that aluminum chloride and sodium metabisulfite could induce lipid peroxidation in sensitive fungi, which may promote the ensuing loss of integrity in the plasma membrane. This direct effect on fungal membranes may contribute, at least in part, to the observed antimicrobial effects of these two salts.

scholarly journals Chromatin Dynamics Contribute to the Spatiotemporal Expression Pattern of Virulence Genes in a Fungal Plant Pathogen

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Lukas Meile ◽  
Jules Peter ◽  
Guido Puccetti ◽  
Julien Alassimone ◽  
Bruce A. McDonald ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Plant Pathogens ◽  
Chromatin Modifications ◽  
Zymoseptoria Tritici ◽  
Content Type ◽  
Spatiotemporal Expression ◽  
Effector Genes ◽  
Fungal Plant Pathogens ◽  
Fungal Plant Pathogen

ABSTRACT Dynamic changes in transcription profiles are key for the success of pathogens in colonizing their hosts. In many pathogens, genes associated with virulence, such as effector genes, are located in regions of the genome that are rich in transposable elements and heterochromatin. The contribution of chromatin modifications to gene expression in pathogens remains largely unknown. Using a combination of a reporter gene-based approach and chromatin immunoprecipitation, we show that the heterochromatic environment of effector genes in the fungal plant pathogen Zymoseptoria tritici is a key regulator of their specific spatiotemporal expression patterns. Enrichment in trimethylated lysine 27 of histone H3 dictates the repression of effector genes in the absence of the host. Chromatin decondensation during host colonization, featuring a reduction in this repressive modification, indicates a major role for epigenetics in effector gene induction. Our results illustrate that chromatin modifications triggered during host colonization determine the specific expression profile of effector genes at the cellular level and, hence, provide new insights into the regulation of virulence in fungal plant pathogens. IMPORTANCE Fungal plant pathogens possess a large repertoire of genes encoding putative effectors, which are crucial for infection. Many of these genes are expressed at low levels in the absence of the host but are strongly induced at specific stages of the infection. The mechanisms underlying this transcriptional reprogramming remain largely unknown. We investigated the role of the genomic environment and associated chromatin modifications of effector genes in controlling their expression pattern in the fungal wheat pathogen Zymoseptoria tritici. Depending on their genomic location, effector genes are epigenetically repressed in the absence of the host and during the initial stages of infection. Derepression of effector genes occurs mainly during and after penetration of plant leaves and is associated with changes in histone modifications. Our work demonstrates the role of chromatin in shaping the expression of virulence components and, thereby, the interaction between fungal pathogens and their plant hosts.

Fungal plant pathogens and soil biodiversity

2003 ◽  
Vol 83 (Special Issue) ◽  
pp. 331-336 ◽  
Author(s):  
R. D. Reeleder
Keyword(s):  
Disease Control ◽  
Management Strategy ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Molecular Techniques ◽  
Control Measures ◽  
Soil Biodiversity ◽  
Naturally Occurring ◽  
Fungal Plant Pathogens

The role of biodiversity as it affects the control of soil-borne fungal pathogens is discussed. Soil-borne fungal plant pathogens have often proven difficult to manage with conventional methods of disease control. Nonetheless, researchers have characterized several naturally occurring “disease-suppressive” soils where crop loss from disease is less than would otherwise be expected. Suppressive soils can also result from the incorporation of various amendments into soil. In most cases, disease control in such soils has been shown to be biological in nature; that is, soil organisms appear to directly or indirectly inhibit the development of disease. Increased knowledge of the identity and functioning of these organisms may support the development of techniques that can be used to develop suppressiveness in soils that are otherwise disease-conducive. Populations of pathogens themselves have been shown to exhibit considerable genetic diversity; the ability of populations to respond to disease control measures should be considered when developing a management strategy. New molecular techniques can be exploited to better characterize soil communities, including the pathogens themselves, as well as community responses to various disease control options. The contributions of Canadian researchers to these areas are discussed and models for further study are proposed. Key words: Biocontrol, molecular technologies, functional diversity, integrated pest management

scholarly journals Towards the Forest Virome: High-Throughput Sequencing Drastically Expands Our Understanding on Virosphere in Temperate Forest Ecosystems

2021 ◽  
Vol 9 (8) ◽  
pp. 1730
Author(s):  
Artemis Rumbou ◽  
Eeva J. Vainio ◽  
Carmen Büttner
Keyword(s):  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Plant Protection ◽  
Forest Health ◽  
Practical Applications ◽  
Fungal Plant Pathogens ◽  
Fungal Associates ◽  
Quantitative Impact ◽  
Symbiotic Microbiota

Thanks to the development of HTS technologies, a vast amount of genetic information on the virosphere of temperate forests has been gained in the last seven years. To estimate the qualitative/quantitative impact of HTS on forest virology, we have summarized viruses affecting major tree/shrub species and their fungal associates, including fungal plant pathogens, mutualists and saprotrophs. The contribution of HTS methods is extremely significant for forest virology. Reviewed data on viral presence in holobionts allowed us a first attempt to address the role of virome in holobionts. Forest health is dependent on the variability of microorganisms interacting with the host tree/holobiont; symbiotic microbiota and pathogens engage in a permanent interplay, which influences the host. Through virus–virus interplays synergistic or antagonistic relations may evolve, which may drastically affect the health of the holobiont. Novel insights of these interplays may allow practical applications for forest plant protection based on endophytes and mycovirus biocontrol agents. The current analysis is conceived in light of the prospect that novel viruses may initiate an emergent infectious disease and that measures for the avoidance of future outbreaks in forests should be considered.

Regulation and Dynamics of Gene Expression During the Life Cycle of Fusarium graminearum

2020 ◽  
Vol 110 (8) ◽  
pp. 1368-1374
Author(s):  
Elizabeth K. Brauer ◽  
Rajagopal Subramaniam ◽  
Linda J. Harris
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Transcriptional Profiling ◽  
Fungal Plant Pathogens ◽  
Essential Components ◽  
Host Infection

Fungal pathogens survive harsh environments and overcome physical, temporal, and chemical barriers to colonize their hosts and reproduce. Fusarium graminearum was one of the first fungal plant pathogens for which transcriptomic tools were developed, making analysis of gene expression a cornerstone approach in studying its biology. The analysis of gene expression in diverse in vitro conditions and during infection of different cereal crops has revealed subsets of both unique and shared transcriptionally regulated genes. Together with genetic studies, these approaches have enhanced our understanding of the development and infection cycle of this economically important pathogen. Here, we will outline recent advances in transcriptional profiling during sporogenesis, spore germination, vegetative growth, and host infection. Several transcriptional regulators have been identified as essential components in these responses and the role of select transcription factors will be highlighted. Finally, we describe some of the gaps in our understanding of F. graminearum biology and how expression analysis could help to address these gaps.

Adaptation and response to mycotoxin presence in pathogen-pathogen interactions within the Fusarium genus

2016 ◽  
Vol 9 (4) ◽  
pp. 565-575 ◽  
Author(s):  
A. Dawidziuk ◽  
G. Koczyk ◽  
D. Popiel
Keyword(s):  
Fusarium Graminearum ◽  
Plant Pathogens ◽  
Fusarium Verticillioides ◽  
Warning Signal ◽  
Resistance Mechanisms ◽  
Growth Patterns ◽  
Fungal Plant Pathogens ◽  
Low Concentrations ◽  
Dose Dependent

The ability of fungal plant pathogens to exude bioactive compounds is an important element of competition in a changing environment. The filamentous fungi usually retain a number of adaptations related not only to the production of toxic compounds by themselves but also to the mitigation of exogenous influences by toxins present in the environment. We examined a distinct effect of toxins on morphology, growth patterns and gene expression after stimulation in mycotoxin-producing and nonproducing isolates representing four evolutionarily divergent species (and chemotypes) within the Fusarium genus (Fusarium graminearum, Fusarium oxysporum, Fusarium proliferatum and Fusarium verticillioides). The aim of our work was to investigate the influence of mycotoxins present in the environment on fungal isolates belonging to evolutionarily divergent complexes within Fusarium genus. The results point to retention of resistance mechanisms in non-producer isolates (F. oxysporum) and specific dose-dependent differences in response to other mycotoxins. In particular, the growth of Fusarium graminearum (confirmed zearalenone and trichothecene producer) was shown to be significantly inhibited by fumonisin B1 and deoxynivalenol. Conversely, spread of Fusarium verticillioides was accelerated by low concentrations (0.5 mg/l) of nivalenol and zearalenone and deoxynivalenol addition resulted in upregulation of the fumonisin poliketyde synthase (FUM1). The basics of competition between divergent fusaria can be described by ‘rock-paper-scissors’ theory, but some of the effects can be explained by other interactions, e.g. autotoxicity of deoxynivalenol and the potential role of low doses of trichothecenes and zearalenone acting as a ‘warning signal’ for competing species.

scholarly journals Near-Complete Genomes of Two Trichoderma Species: A Resource for Biological Control of Plant Pathogens

2020 ◽  
Vol 33 (8) ◽  
pp. 1036-1039 ◽  
Author(s):  
Yi Zhou ◽  
Yilian Wang ◽  
Kai Chen ◽  
Yuanzheng Wu ◽  
Jindong Hu ◽  
...  
Keyword(s):  
Biological Control ◽  
Enzyme Production ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Effective Control ◽  
Control Mechanisms ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Genome Data ◽  
Fungal Plant Pathogens

Trichoderma species are widely used to control fungal and nematode diseases of crops. To date, only one complete Trichoderma genome has been sequenced, T. reesei QM6a, a model fungus for industrial enzyme production, while the species or strains used for biological control of plant diseases are only available as draft genomes. Previously, we demonstrated that two Trichoderma strains (T. afroharzianum and T. cyanodichotomus) provide effective control of nematode and fungal plant pathogens. Based on deep sequencing using Illumina and Pacbio platforms, we have assembled high-quality genomes of the above two strains, with contig N50 reaching 4.2 and 1.7 Mbp, respectively, which is greater than those of published draft genomes. The genome data will provide a resource to assist research on the biological control mechanisms of Trichoderma spp.

scholarly journals Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium

2020 ◽  
Vol 6 (4) ◽  
pp. 263
Author(s):  
Claudia Stracquadanio ◽  
Juan Manuel Quiles ◽  
Giuseppe Meca ◽  
Santa Olga Cacciola
Keyword(s):  
Organic Compounds ◽  
Direct Contact ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Antimicrobial Activities ◽  
Bioactive Metabolites ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Minimum Fungicidal Concentration ◽  
Fungal Plant Pathogens

Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radial growth (PIRG) was calculated. The highest PIRG values were 76% and 81% (direct contact) with IMI 393899 and TS, respectively. Nondirect contact does not show inhibition on any of pathogens tested, indicating that the inhibition is not due to the secretion of volatile substances. Culture filtrates were analyzed by GC-MS and HPLC-Q-TOF-MS for the identification of volatile organic compounds (VOCs) and nonvolatile organic compounds (nVOCs), respectively. Seven classes of VOCs and 12 molecules of nVOCs were identified. These results indicate that these strains of Trichoderma had antimicrobial activities and they are potential natural sources of compounds with biological activity.

scholarly journals Unravelling the role of alcohol copper radical oxidases in fungal plant pathogens

2021 ◽  
Author(s):  
Bastien Bissaro ◽  
Sayo Kodama ◽  
Hayat Hage ◽  
David Ribeaucourt ◽  
Mireille Haon ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Crop Protection ◽  
Redox Partner ◽  
Fungal Plant Pathogens ◽  
Plant Cuticles ◽  
Penetration Ability ◽  
Molecular Signals

Abstract Copper radical oxidases (CRO) form a class of enzymes with a longstanding history encompassing diverse substrate specificities. While the biological function of most CROs remains unknown, we observed that CROs active on aliphatic alcohols are found only in fungal plant pathogens. Here, we unveil the role of these CROs and the identity of their natural redox partner, a haem-iron peroxidase. Combining multiscale approaches, we report that Colletotrichum and Magnaporthe appressoria (specialized cells that puncture the plant cuticles) co-secrete this pair of metalloenzymes early during penetration. We show in vivo that mutant appressoria lacking either or both enzymes have impaired penetration ability and pathogenicity. We reveal in vitro a finely-tuned enzyme interplay is responsible for the oxidation of plant cuticular long-chain alcohols into aldehyde products, suggested to act as key molecular signals in the fungal infection machinery. Our results open new avenues to design oxidase-specific inhibitors as anti-penetrants for crop protection.

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