Trichoderma Secondary Metabolites Research Articles

Interaction of the Fungal Metabolite Harzianic Acid with Rare-Earth Cations (La3+, Nd3+, Sm3+, Gd3+).

Rare-earth elements are emerging contaminants of soil and water bodies which destiny in the environment and effects on organisms is modulated by their interactions with natural ligands produced by bacteria, fungi and plants. Within this framework, coordination by harzianic acid (H2L), a Trichoderma secondary metabolite, of a selection of tripositive rare-earth cations Ln3+ (Ln3+ = La3+, Nd3+, Sm3+, and Gd3+) was investigated at 25 °C, and in a CH3OH/0.1 M NaClO4 (50/50 w/w) solvent, using mass spectrometry, circular dichroism, UV–Vis spectrophotometry, and pH measurements. Experimental data can be satisfactorily explained by assuming, for all investigated cations, the formation of a mono-complex (LnL+) and a bis-complex (LnL2−). Differences were found between the formation constants of complexes of different Ln3+ cations, which can be correlated with ionic radius. Since gadolinium is the element that raises the most concern among lanthanide elements, its effects on organisms at different levels of biological organization were explored, in the presence and absence of harzianic acid. Results of ecotoxicological tests suggest that harzianic acid can decrease gadolinium biotoxicity, presumably because of complex formation with Gd3+.

Standardization, Characterization and Isolation of Trichoderma-Silver Nanoparticle-A Pharmaceutical Approach in Field of Nano-Medicine

Silver is a well known antimicrobial agent. It is utilized in many antimicrobial and medication. The Trichoderma and its Metabolites have also been meant for antimicrobial activity against the various bacterial and fungal strain. In the present investigation Nanoparticle of silver is prepared by chemical method, green synthesis using plants and biosynthesis using microbes. Trichoderma secondary metabolite prepared by solvent extraction method from Trichoderma harzianum which act as a capping and reducing agent. The biosynthesised silver Nanoparticles were characterized by UV-Vis spectroscopy and TEM. UV-Vis spectra of silver Nanoparticle and trichoderma extract showed absorption spectra at 420nm & 430 nm respectively while the fused nanoparticle with Trichoderma secondary metabolite showed absorption spectra at 415 nm corresponding to the surface Plasmon resonance of silver Nanoparticle. It was determined the nanoparticle showed absorption spectra at 415 nm and morphology as spherical with size range 8 to 24 nm and providing good antimicrobial activity as Trichoderma silver fused nanoparticle against many microbial strain, so it can be prepared for pharmaceutical approach against the infectious disease caused by clinical pathogenic organisms.

Bioformulations with Beneficial Microbial Consortia, a Bioactive Compound and Plant Biopolymers Modulate Sweet Basil Productivity, Photosynthetic Activity and Metabolites.

Increasing attention is being given to the development of innovative formulations to substitute the use of synthetic chemicals to improve agricultural production and resource use efficiency. Alternatives can include biological products containing beneficial microorganisms and bioactive metabolites able to inhibit plant pathogens, induce systemic resistance and promote plant growth. The efficacy of such bioformulations can be increased by the addition of polymers as adjuvants or carriers. Trichoderma afroharzianum T22, Azotobacter chroococcum 76A and 6-pentyl-α-pyrone (6PP; a Trichoderma secondary metabolite) were administrated singularly or in a consortium, with or without a carboxymethyl cellulose-based biopolymer (BP), and tested on sweet basil (Ocimum basilicum L.) grown in a protected greenhouse. The effect of the treatments on basil yield, photosynthetic activity and secondary metabolites production was assessed. Photosynthetic efficiency was augmented by the applications of the bioformulations. The applications to the rhizosphere with BP + 6PP and BP + T22 + 76A increased the total fresh weight of basil by 26.3% and 23.6%, respectively. Untargeted LC-MS qTOF analysis demonstrated that the plant metabolome was significantly modified by the treatments. Quantification of the profiles for the major phenolic acids indicated that the treatment with the T22 + 76A consortium increased rosmarinic acid content by 110%. The use of innovative bioformulations containing microbes, their metabolites and a biopolymer was found to modulate the cultivation of fresh basil by improving yield and quality, thus providing the opportunity to develop farming systems with minimal impact on the environmental footprint from the agricultural production process.

Determination of antifungal efficiency of some fungicides and secondary metabolites of Trichoderma species against Botrytis cinerea

Aim: The present study aimed to investigate the antifungal effects of fenhexamid, cyprodinil+fludioxanil, Bacillus subtilis QST 713, Trichoderma secondary metabolites (EGE-K-38 and EGE-K-71) on 6 isolates of necrotrophic fungi (Botrytis cinerea) under in- vitro conditions. Methodology: A dual culture technique was used to evaluate the effects of volatile compounds produced by Trichoderma in culture media against Botrytis cinerea isolates. For non-volatile and volatile metabolites, measurements for growth inhibition were made with the mixture of filter sterilized liquid medium of Trichoderma and potato dextrose agar. The fungicidal effects of these non-volatile metabolites and fungicides were first evaluated according to the effective concentration (EC50) data of growing mycelium inhibition of disease agents. Results: According to the results obtained, the drug/agent with the lowest fungicidal activity was determined as fenhexamide, which seems to have the lowest EC50 value of 0.05 ug m l-1. Both non-volatile metabolites and volatile metabolites of Trichoderma strains showed strong inhibition against B. cinerea isolates under experimental conditions. The highest growth inhibition percentage was determined with volatile metabolites of Trihoderma atroviride EGE-K-71 strain as 71.8%. Interpretation: The study suggest that filtrates that contain secondary metabolites and volatile compounds of Trichoderma strains produced in both liquid culture and dual culture conditions can be used as an effective fungal control agents against pre and postharvest contamination of grapes with Botrytis cinerea.

Application of Trichoderma harzianum, 6-pentyl-α-pyrone and Plant Biopolymer Formulations Modulate Plant Metabolism and Fruit Quality of Plum Tomatoes.

Many Trichoderma are successfully used to improve agriculture productivity due to their capacity for biocontrol and to stimulate plant growth and tolerance to abiotic stress. This research elucidates the effect of applications with Trichoderma harzianum strain T22 (T22), or biopolymer (BP) alone or in combination (BP + T22 or BP + 6-pentyl-α-pyrone (6PP); a Trichoderma secondary metabolite) on the crop performance, nutritional and functional quality of greenhouse tomato (Solanum lycopersicum L. cultivar Pixel). T22 elicited significant increases in total yield (+40.1%) compared to untreated tomato. The content of lycopene, an important antioxidant compound in tomatoes, significantly increased upon treatment with T22 (+ 49%), BP + T22 (+ 40%) and BP + 6PP (+ 52%) compared to the control. T22 treatments significantly increased the content of asparagine (+37%), GABA (+87%) and MEA (+102%) over the control; whereas BP alone strongly increased GABA (+105%) and MEA (+85%). The synthesis of these compounds implies that tomato plants are able to reuse the photorespiratory amino acids and ammonium for producing useful metabolites and reduce the pressure of photorespiration on plant metabolism, thus optimizing photosynthesis and growth. Finally, these metabolites exert many beneficial effects for human health, thus enhancing the premium quality of plum tomatoes.

Trichoderma Secondary Metabolites Active on Plants and Fungal Pathogens

Beneficial microbes typically produce bioactive molecules that can affect the interactions of plants with their pathogens. Many secondary metabolites may also have antibiotic properties, which enable the producing microbe to inhibit and/or kill other microorganisms i.e. competing for a nutritional niche. Indeed, some of these compounds have been found to play an important role in the biocontrol of plant diseases by various beneficial microbes used world-wide for crop protection and bio-fertilization. In addition to direct toxic activity against plant pathogens, biocontrol-related metabolites may also increase disease resistance by triggering systemic plant defence activity, and/or enhance root and shoot growth. Fungi belonging to the Trichoderma genus are well known producers of secondary metabolites with a direct activity against phytopathogens and compounds that substantially affect the metabolism of the plant. The widescale application of selected metabolites to induce host resistance and/or to promote crop yield may become a reality in the near future and represents a powerful tool for the implementation of IPM strategies.

A novel fungal metabolite with beneficial properties for agricultural applications.

Trichoderma are ubiquitous soil fungi that include species widely used as biocontrol agents in agriculture. Many isolates are known to secrete several secondary metabolites with different biological activities towards plants and other microbes. Harzianic acid (HA) is a T. harzianum metabolite able to promote plant growth and strongly bind iron. In this work, we isolated from the culture filtrate of a T. harzianum strain a new metabolite, named isoharzianic acid (iso-HA), a stereoisomer of HA. The structure and absolute configuration of this compound has been determined by spectroscopic methods, including UV-Vis, MS, 1D and 2D NMR analyses. In vitro applications of iso-HA inhibited the mycelium radial growth of Sclerotinia sclerotiorum and Rhizoctonia solani. Moreover, iso HA improved the germination of tomato seeds and induced disease resistance. HPLC-DAD experiments showed that the production of HA and iso HA was affected by the presence of plant tissue in the liquid medium. In particular, tomato tissue elicited the production of HA but negatively modulated the biosynthesis of its analogue iso-HA, suggesting that different forms of the same Trichoderma secondary metabolite have specific roles in the molecular mechanism regulating the Trichoderma plant interaction.

Harzianic acid: a novel siderophore fromTrichoderma harzianum

Agriculture-relevant microorganisms are considered to produce secondary metabolites during processes of competition with other micro- and macro-organisms, symbiosis, parasitism or pathogenesis. Many different strains of the genus Trichoderma, in addition to a direct activity against phytopathogens, are well-known producers of secondary metabolites and compounds that substantially affect the metabolism of the host plant. Harzianic acid is a Trichoderma secondary metabolite, showing antifungal and plant growth promotion activities. This report demonstrates the ability of this tetramic acid to bind with a good affinity essential metals such as Fe(3+) , which may represent a mechanism of iron solubilisation that significantly alters nutrient availability in the soil environment for other microorganisms and the host plant.

Trichoderma Secondary Metabolites that Affect Plant Metabolism

Recently, there have been many exciting new developments relating to the use of Trichoderma spp. as agents for biocontrol of pathogens and as plant growth promoters. Several mechanisms have been proposed to explain the positive effects of these microorganisms on the plant host. One factor that contributes to their beneficial biological activities is related to the wide variety of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth and pathogenic activities of the parasites, but also to increase disease resistance by triggering the system of defence in the plant host. In addition, these metabolites are also capable of enhancing plant growth, which enables the plant to counteract the disease with compensatory vegetative growth by the augmented production of root and shoot systems. This review takes into account the Trichoderma secondary metabolites that affect plant metabolism and that may play an important role in the complex interactions of this biocontrol agent with the plant and pathogens.

A novel role for Trichoderma secondary metabolites in the interactions with plants

Secondary metabolites play a pivotal role in the antagonistic activities of some biocontrol species of Trichoderma resulting in the suppression of plant pathogens, but their involvement in complex interactions with plants has not been specifically studied. In this work the major secondary metabolites produced by biocontrol strains of Trichoderma ( T. harzianum strains T22, T39 and A6, and T. atroviride strain P1) have been investigated for their effect on plant growth promotion. An auxin-like activity was observed on etiolated pea ( Pisum sativum) stems treated with harzianolide and 6- n-pentyl-6 H-pyran-2-one (6PP), which also affected the growth of tomato ( Lycopersicum esculentum) and canola ( Brassica napus) seedlings. The ability of these molecules to induce systemic defence responses in planta was also investigated. Tomato and oil-seed rape seedlings were treated with the metabolites and then inoculated with a spore suspension of Botrytis cinerea or Leptosphaeria maculans, respectively. In both cases, a reduction of disease symptoms was observed, particularly on 6PP-treated plants. Moreover an over-expression of pathogenesis-related (PR) proteins was also detected in treated plants. These results clearly indicate that secondary metabolites of Trichoderma spp. may have a role in both plant growth regulation and activation of plant defence responses.

Trichoderma harzianum and its Metabolite 6‐Pentyl‐alpha‐pyrone Suppress Fusaric Acid Produced by Fusarium moniliforme

AbstractThe interaction of the pathogen Fusarium moniliforme and two antagonistic Trichoderma harzianum isolates was studied especially with respect to their secondary metabolites fusaric acid (FA) and 6‐pentyl‐alpha‐pyrone (6PAP). Among 10 isolates of F. moniliforme screened for FA production on maize kernels, the isolate 8 accumulated the highest amount of FA (678 μg/g). Mycelial growth and production of FA by isolate 8, determined in different liquid media revealed that the highest biomass and FA were produced in Czapek Dox Broth (CDB) followed by Richard’s solution. The amount of FA per gram mycelial dry weight reached its maximum in CDB and Richard’s solution after 14 days of incubation. Mycelial growth and conidia production of both Trichoderma isolates (T16 and T23) were retarded by increasing concentrations of FA in agar medium. At FA concentration of 300 mg/ml the radial mycelial growth of the isolates T16 and T23 were retarded by 32.5% and 45%, respectively. Conidia production was diminished in a similar extent as mycelial growth. Both T. harzianum isolates were capable to degrade FA in potato dextrose broth medium, particularly when lower doses of FA were present. In the presence of 50 mg/ml FA in the culture medium, the isolates T23 and T16 reduced FA by 51.4% and 88.4%, respectively, 9 days post‐inoculation. The antifungal metabolite 6PAP, isolated from T. harzianum T23 cultures, was introduced at different concentrations into 2‐day‐old cultures of F. moniliforme. After further 5 days of incubation of F. moniliforme in the presence of 6PAP, the FA contents per gram mycelial dry weight were significantly decreased compared to control cultures where 6PAP was absent. Dosages of 300 and 400 mg/l of 6PAP in the cultures retarded FA accumulations by 62.5% and 77.2%, respectively. The current results, however, provided the first evidence for activity of 6PAP, as a Trichoderma secondary metabolite, on degrading/synthesis suppression of the Fusarium toxin FA.

Biotransformation of the Trichoderma metabolite 6- n-pentyl-2 H-pyran-2-one by cell suspension cultures of Pinus radiata

Cell suspension cultures of Pinus radiata metabolize the antifungal Trichoderma secondary metabolite 6- n-pentyl-2 H-pyran-2-one (6PAP) ( 1) via hydroxylation of the pentyl side chain. Examination of the culture medium following dosing studies with 1 revealed that 79–85% of this bioactive compound had been metabolised after 144 h. At that time, 34–40% of the metabolized dose was recovered as a series of monohydroxylated isomers of 1, the principal metabolite being 5-(2-pyron-6-yl)pentan-5-ol ( 7).

Trichoderma /pathogen interactions: measurement of antagonistic chemicals produced at the antagonist/pathogen interface using a tubular bioassay

A tubular bioassay was used to measure analytically the local production and concentration of the antifungal Trichoderma secondary metabolite 6‐n‐pentyl‐2H‐pyran‐2‐one (6PAP) at the Trichoderma antagonist/pathogen interface. 6PAP levels significantly increased in the presence of the pathogen Botrytis cinerea, typically 300–700%, and were highest near the pathogen source. The level of response for a particular Trichoderma isolate was found to vary with the test organism used. Two products produced by biotransformation of 6PAP by B. cinerea in response to the interaction were also detected.