Trichoderma Secondary Metabolites Active on Plants and Fungal Pathogens

Pathogens belonging to the Fusarium genus are causal agents of the most significant crop diseases worldwide. Virtually all Fusarium species synthesize toxic secondary metabolites, known as mycotoxins; however, the roles of mycotoxins are not yet fully understood. To understand how a fungal partner alters its lifestyle to assimilate with the plant host remains a challenge. The review presented the mechanisms of mycotoxin biosynthesis in the Fusarium genus under various environmental conditions, such as pH, temperature, moisture content, and nitrogen source. It also concentrated on plant metabolic pathways and cytogenetic changes that are influenced as a consequence of mycotoxin confrontations. Moreover, we looked through special secondary metabolite production and mycotoxins specific for some significant fungal pathogens-plant host models. Plant strategies of avoiding the Fusarium mycotoxins were also discussed. Finally, we outlined the studies on the potential of plant secondary metabolites in defense reaction to Fusarium infection.

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Olea europaea L. Root Endophyte Bacillus velezensis OEE1 Counteracts Oomycete and Fungal Harmful Pathogens and Harbours a Large Repertoire of Secreted and Volatile Metabolites and Beneficial Functional Genes

Microorganisms ◽

10.3390/microorganisms7090314 ◽

2019 ◽

Vol 7 (9) ◽

pp. 314 ◽

Cited By ~ 8

Author(s):

Manel Cheffi ◽

Ali Chenari Bouket ◽

Faizah N. Alenezi ◽

Lenka Luptakova ◽

Marta Belka ◽

...

Keyword(s):

Secondary Metabolites ◽

Plant Growth ◽

Fungal Pathogens ◽

Biocontrol Agents ◽

Economic Losses ◽

Bacillus Velezensis ◽

Strong Activity ◽

Rarefaction Analysis ◽

Olive Trees ◽

Large Repertoire

Oomycete and fungal pathogens, mainly Phytophthora and Fusarium species, are notorious causal agents of huge economic losses and environmental damages. For instance, Phytophthora ramorum, Phytophthora cryptogea, Phytophthora plurivora and Fusarium solani cause significant losses in nurseries and in forest ecosystems. Chemical treatments, while harmful to the environment and human health, have been proved to have little or no impact on these species. Recently, biocontrol bacterial species were used to cope with these pathogens and have shown promising prospects towards sustainable and eco-friendly agricultural practices. Olive trees prone to Phytophthora and Fusarium disease outbreaks are suitable for habitat-adapted symbiotic strategies, to recover oomycetes and fungal pathogen biocontrol agents. Using this strategy, we showed that olive trees-associated microbiome represents a valuable source for microorganisms, promoting plant growth and healthy benefits in addition to being biocontrol agents against oomycete and fungal diseases. Isolation, characterization and screening of root microbiome of olive trees against numerous Phytophthora and other fungal pathogens have led to the identification of the Bacillus velezensis OEE1, with plant growth promotion (PGP) abilities and strong activity against major oomycete and fungal pathogens. Phylogenomic analysis of the strain OEE1 showed that B. velezensis suffers taxonomic imprecision that blurs species delimitation, impacting their biofertilizers’ practical use. Genome mining of several B. velezensis strains available in the GenBank have highlighted a wide array of plant growth promoting rhizobacteria (PGPR) features, metals and antibiotics resistance and the degradation ability of phytotoxic aromatic compounds. Strain OEE1 harbours a large repertoire of secreted and volatile secondary metabolites. Rarefaction analysis of secondary metabolites richness in the B. velezenis genomes, unambiguously documented new secondary metabolites from ongoing genome sequencing efforts that warrants more efforts in order to assess the huge diversity in the species. Comparative genomics indicated that B. velezensis harbours a core genome endowed with PGP features and accessory genome encoding diverse secondary metabolites. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of OEE1 Volatile Organic Compounds (VOCs) and Liquid Chromatography High Resolution Mas Spectrometry (LC-HRMS) analysis of secondary metabolites identified numerous molecules with PGP abilities that are known to interfere with pathogen development. Moreover, B. velezensis OEE1 proved effective in protecting olive trees against F. solani in greenhouse experiments and are able to inhabit olive tree roots. Our strategy provides an effective means for isolation of biocontrol agents against recalcitrant pathogens. Their genomic analysis provides necessary clues towards their efficient implementation as biofertilizers.

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Anti-fungal secondary metabolites and hydrolytic enzymes from rhizospheric bacteria in crop protection: a review

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v44i2.51452 ◽

2021 ◽

Vol 44 (2) ◽

pp. 69-84

Author(s):

Farhana Tasnim Chowdhury ◽

Nazia Rifat Zaman ◽

Mohammad Riazul Islam ◽

Haseena Khan

Keyword(s):

Secondary Metabolites ◽

Plant Growth ◽

Fungal Pathogens ◽

Hydrolytic Enzymes ◽

Plant Growth Promoting Rhizobacteria ◽

Field Conditions ◽

Plant Host ◽

Wide Range ◽

Plant Growth Promoting ◽

Growth Promoting

Plant growth promoting rhizobacteria (PGPR) residing in soil rhizosphere provide enormous beneficial effects to a plant host producing diverse secondary metabolites and enzymes useful for plant growth and protection. Siderophores, antibiotics, volatile compounds and hydrolytic enzymes are the major molecules secreted by the PGPRs, which have substantial antifungal properties and can provide plant protection. These compounds are responsible for the lysis and hyperparasitism of antagonists against deleterious fungal pathogens. Siderophore-producing PGPRs function by depriving the pathogen of iron nutrition. Antibiotics have been reported to be involved in the suppression of different fungal pathogens by inducing fungistasis, inhibition of spore germination, lysis of fungal mycelia. The PGPRs also secrete a wide range of low molecular weight volatile organic compounds (VOCs) that inhibit mycelial growth, sporulation, germination of phytophathogenic fungi, etc. Hydrolytic enzymes, mostly chitinase, protease and cellulose, lyse the cell wall of fungi. Therefore, plant growth-promoting rhizobacteria can be considered as an effective, eco-friendly, and sustainable replacement to the chemical fungicides. There are many PGPRs that perform very well in controlled conditions but not in field conditions, and hence the commercializing of hese products is not easy. Development of formulations with increased shelf life, a broad spectrum of action and consistent performance under field conditions can pave the way for commercializing the PGPRs at a faster rate. Journal of Bangladesh Academy of Sciences, Vol. 44, No. 2, 69-84, 2020

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Notopterygium incisum extract and associated secondary metabolites inhibit apple fruit fungal pathogens

Pesticide Biochemistry and Physiology ◽

10.1016/j.pestbp.2018.07.001 ◽

2018 ◽

Vol 150 ◽

pp. 59-65 ◽

Cited By ~ 4

Author(s):

Lin Xiao ◽

Yuan-Ming Zhou ◽

Xiang-Fei Zhang ◽

Feng-Yu Du

Keyword(s):

Secondary Metabolites ◽

Fungal Pathogens ◽

Apple Fruit

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In Vitro Antibacterial, Antifungal, Nematocidal and Growth Promoting Activities of Trichoderma hamatum FB10 and Its Secondary Metabolites

Journal of Fungi ◽

10.3390/jof7050331 ◽

2021 ◽

Vol 7 (5) ◽

pp. 331

Author(s):

Alaa Baazeem ◽

Abdulaziz Almanea ◽

Palanisamy Manikandan ◽

Mohammed Alorabi ◽

Ponnuswamy Vijayaraghavan ◽

...

Keyword(s):

Secondary Metabolites ◽

Secondary Metabolite ◽

Fungal Pathogens ◽

Xanthomonas Campestris ◽

Green Gram ◽

Control Group ◽

Cell Free Extract ◽

Trichoderma Hamatum ◽

Growth Promoting

Microbial natural biocides have attracted much more attention in recent years in order to avoid the unrestricted use of chemical biocides in the environment. The aim of this study is to analyze the antibacterial and antifungal activities of secondary metabolites and growth promoting, nematicidal, and soil enzyme activity mediated by Trichoderma hamatum FB10. The bactericidal and fungicidal activities were performed using cell-free extract. Results revealed that the selected strain exert antibacterial activity against Acidovorax avenae, Erutimacarafavora, and Xanthomonas campestris. The selected fungal strain FB10 showed antagonistic activity against fungal pathogens such as, S. sclerotiorum, Rhizoctonia solani, Alternaria radicina, Alternaria citri, and Alternaria dauci. Among the bacterial pathogens, A. avenae showed least MIC (30 ± 2.5 µg/mL) and MBC (70 ± 1.25 µg/mL) values. T. hamatum FB10 strain synthesized bioactive volatile secondary metabolite, which effectively inhibited the growth of bacteria and fungi and indicated the presence of 6-pentyl-alpha-pyrone as the major compound (67.05%). The secondary metabolite synthesized by T. hamatum FB10 showed nematicidal activity against M. incognita eggs. Egg hatch inhibition was 78 ± 2.6% and juvenile stage mortality rate was 89 ± 2.5% when the strain FB10 was treated with nematode. The cell free extract of T. hamatum FB10 showed protease, amylase, cellulase, chitinase, glucanase activities. T. hamatum FB10 inoculated with green gram increased 11% plant height, compared to the control. The fresh weight of the experimental group inoculated with T. hamatum FB10 increased 33.6% more compared to the control group. The green gram seedlings inoculated with T. hamatum FB10 increased 18% more dry weight than control group. Soil enzymes such as, urease, phosphatase, catalase and saccharase were improved in the soil inoculated with T. hamatum FB10. These biochemical components play potent role in soil fertility, energy conversion, and in soil organic matter conversion.

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Oligosaccharides Derived from Tramesan: Their Structure and Activity on Mycotoxin Inhibition in Aspergillus flavus and Aspergillus carbonarius

Biomolecules ◽

10.3390/biom11020243 ◽

2021 ◽

Vol 11 (2) ◽

pp. 243

Author(s):

Jelena Loncar ◽

Barbara Bellich ◽

Alessia Parroni ◽

Massimo Reverberi ◽

Roberto Rizzo ◽

...

Keyword(s):

Secondary Metabolites ◽

Trametes Versicolor ◽

Fungal Pathogens ◽

Crop Protection ◽

Main Tool ◽

Aspergillus Carbonarius ◽

Food And Feed ◽

Feed Safety ◽

Structure And Activity ◽

Food And Feed Safety

Food and feed safety are of paramount relevance in everyday life. The awareness that different chemicals, e.g., those largely used in agriculture, could present both environmental problems and health hazards, has led to a large limitation of their use. Chemicals were also the main tool in a control of fungal pathogens and their secondary metabolites, mycotoxins. There is a drive to develop more environmentally friendly, “green”, approaches to control mycotoxin contamination of foodstuffs. Different mushroom metabolites showed the potential to act as control agents against mycotoxin production. The use of a polysaccharide, Tramesan, extracted from the basidiomycete Trametes versicolor, for controlling biosynthesis of aflatoxin B1 and ochratoxin A, has been previously discussed. In this study, oligosaccharides obtained from Tramesan were evaluated. The purified exopolysaccharide of T. versicolor was partially hydrolyzed and separated by chromatography into fractions from disaccharides to heptasaccharides. Each fraction was individually tested for mycotoxin inhibition in A. flavus and A. carbonarius. Fragments smaller than seven units showed no significant effect on mycotoxin inhibition; heptasaccharides showed inhibitory activity of up to 90% in both fungi. These results indicated that these oligosaccharides could be used as natural alternatives to crop protection chemicals for controlling these two mycotoxins.

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Fusarium Head Blight, Mycotoxins and Strategies for Their Reduction

Agronomy ◽

10.3390/agronomy10040509 ◽

2020 ◽

Vol 10 (4) ◽

pp. 509 ◽

Cited By ~ 6

Author(s):

Elżbieta Mielniczuk ◽

Barbara Skwaryło-Bednarz

Keyword(s):

Secondary Metabolites ◽

Fungal Pathogens ◽

Plant Protection ◽

Fusarium Species ◽

Fumonisin B1 ◽

Agricultural Practices ◽

Weather Conditions ◽

Head Blight ◽

Before And After ◽

Safe Food

Mycotoxins are secondary metabolites of microscopic fungi, which commonly contaminate cereal grains. Contamination of small-grain cereals and maize with toxic metabolites of fungi, both pathogenic and saprotrophic, is one of the particularly important problems in global agriculture. Fusarium species are among the dangerous cereal pathogens with a high toxicity potential. Secondary metabolites of these fungi, such as deoxynivalenol, zearalenone and fumonisin B1 are among five most important mycotoxins on a European and world scale. The use of various methods to limit the development of Fusarium cereal head diseases and grain contamination with mycotoxins, before and after harvest, is an important element of sustainable agriculture and production of safe food. The applied strategies utilize chemical and non-chemical methods, including agronomic, physical and biological treatments. Biological methods now occupy a special place in plant protection as an element of biocontrol of fungal pathogens by inhibiting their development and reducing mycotoxins in grain. According to the literature, Good Agricultural Practices are the best line of defense for controlling Fusarium toxin contamination of cereal and maize grains. However, fluctuations in weather conditions can significantly reduce the effectiveness of plants protection methods against infection with Fusarium spp. and grain accumulation of mycotoxins.

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Test Antifungal Phatogen Extract Secondary Metabolites Of Endophytic Fungi Raru Plant (Cotylelobium melanoxylon)

JURNAL BIOSAINS ◽

10.24114/jbio.v1i2.2781 ◽

2016 ◽

Vol 1 (2) ◽

pp. 6

Author(s):

Uswatun Hasanah ◽

Riwayati Riwayati ◽

Idramsa Idramsa

Keyword(s):

Candida Albicans ◽

Secondary Metabolites ◽

Endophytic Fungi ◽

Fungal Pathogens ◽

Pathogenic Fungus ◽

Sclerotium Rolfsii ◽

Pathogenic Fungi ◽

Inhibition Zone ◽

Clear Zone ◽

Paper Disc

This study aims to determine the ability of extracts secondary metabolites of endophytic fungi raru plant Siarang (Cotylelobium melanoxylon) in inhibiting the growth of pathogenic fungi. Pathogenic fungi tested were Collectotrichum, Fusarium oxysporum, Candida albicans and Sclerotium rolfsii. Test antifungal pathogens carried out by using the method of Kirby-Bour, ie by measuring the clear zone located around the paper disc which is the zone of growth inhibition of pathogenic fungi. Measurement of inhibition zone is done by using a caliper or ruler. The results showed that the secondary metabolites of endophytic fungi extracts could inhibit the growth of pathogenic fungus Candida albicans is the clear zone of 10.23 mm. Keywords : endophytic fungus, Cotylelobium melanoxylon, extract of secondary metabolites, fungal pathogens, inhibition zone

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Human and Plant Fungal Pathogens: The Role of Secondary Metabolites

PLoS Pathogens ◽

10.1371/journal.ppat.1003859 ◽

2014 ◽

Vol 10 (1) ◽

pp. e1003859 ◽

Cited By ~ 82

Author(s):

Daniel H. Scharf ◽

Thorsten Heinekamp ◽

Axel A. Brakhage

Keyword(s):

Secondary Metabolites ◽

Fungal Pathogens

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