Showing papers on "Trichoderma harzianum published in 2012"

The qid74 gene from Trichoderma harzianum has a role in root architecture and plant biofertilization

Abstract: The Trichoderma harzianum qid74 gene encodes a cysteine-rich cell wall protein that has an important role in adherence to hydrophobic surfaces and cellular protection; this gene was upregulated in Trichoderma high-density oligonucleotide (HDO) microarrays in interaction with tomato roots. Using a collection of qid74-overexpressing and disrupted mutants the role of this gene in cucumber and tomato root architecture was analysed in hydroponic and soil systems under greenhouse conditions. No significant differences were found in the pattern of root colonization and the length of primary roots of cucumber or tomato plants inoculated by T. harzianum CECT 2413 wild-type (wt) strain or any of the qid74 transformants. However, compared to the wt treatment, lateral roots were significantly longer in plants inoculated with the overexpressing transformants, and shorter in those treated with the disruptant strains. Microscopic observations revealed more and longer secondary root hairs in cucumber plants treated with the qid74-overexpressing mutants and fewer and shorter hairs in roots treated with qid74-disrupted transformants, compared to those observed in plants inoculated with the wt strain. qid74-induced modifications in root architecture increased the total absorptive surface, facilitating nutrient uptake and translocation of nutrients in the shoots, resulting in increased plant biomass through an efficient use of NPK and micronutrients.

Trichoderma harzianum Enhances Antioxidant Defense of Tomato Seedlings and Resistance to Water Deficit

Abstract: Some plant-symbiotic strains of the genus Trichoderma colonize roots and induce profound changes in plant gene expression that lead to enhanced growth, especially under biotic and abiotic stresses. In this study, we tested the hypothesis that one of the protective mechanisms enhanced by T. harzianum T22 colonization is the antioxidant defense mechanism. Having established that strain T22 modulates the expression of the genes encoding antioxidant enzymes, the status of antioxidant defense of tomato seedlings in response to colonization by T22 and water deficit was investigated. Total ascorbate or glutathione levels were not affected by either stimuli, but under water deficit, antioxidant pools became more oxidized (lower ratios of reduced to oxidized forms), whereas colonized plants maintained redox state as high as or higher than unstressed and untreated plants. The enhanced redox state of colonized plants could be explained by their higher activity of ascorbate and glutathione-recycling enzymes, higher activity of superoxide dismutase, catalase, and ascorbate peroxidase, in both root and shoot throughout the experiment. Similar enzymes were induced in uncolonized plants in response to water-deficit stress but to a lower extent when compared with colonized plants. This orchestrated enhancement in activity of reactive oxygen species (ROS)-scavenging pathways in colonized plants in response to stress supports the hypothesis that enhanced resistance of colonized plants to water deficit is at least partly due to higher capacity to scavenge ROS and recycle oxidized ascorbate and glutathione, a mechanism that is expected to enhance tolerance to abiotic and biotic stresses.

Microbial consortium-mediated reprogramming of defence network in pea to enhance tolerance against Sclerotinia sclerotiorum.

Abstract: Aims: To evaluate the potentiality of three rhizosphere microorganisms in suppression of Sclerotinia rot in pea in consortia mode and their impact on host defence responses. Methods and Results: Pseudomonas aeruginosa PJHU15, Trichoderma harzianum TNHU27 and Bacillus subtilis BHHU100 from rhizospheric soils were selected based on compatibility, antagonistic and plant growth promotion activities. The microbes were used as consortia to assess their ability to trigger the phenylpropanoid and antioxidant activities and accumulation of proline, total phenol and pathogenesis-related (PR) proteins in pea under the challenge of the soft-rot pathogen Sclerotinia sclerotiorum. The triple-microbe consortium and single-microbe treatments showed 1·4–2·3 and 1·1–1·7-fold increment in defence parameters, respectively, when compared to untreated challenged control. Activation of the phenylpropanoid pathway and accumulation of total phenolics were highest at 48 h, whereas accumulation of proline and PR proteins along with activities of the antioxidant enzymes was highest at 72 h. Conclusions: The compatible microbial consortia triggered defence responses in an enhanced level in pea than the microbes alone and provided better protection against Sclerotinia rot. Significance and Impact of the Study: Rhizosphere microbes in consortium can enhance protection in pea against the soft-rot pathogen through augmented elicitation of host defence responses.

Downy mildew resistance induced by Trichoderma harzianum T39 in susceptible grapevines partially mimics transcriptional changes of resistant genotypes

Abstract: Downy mildew, caused by Plasmopara viticola, is one of the most severe diseases of grapevine and is commonly controlled by fungicide treatments. The beneficial microorganism Trichoderma harzianum T39 (T39) can induce resistance to downy mildew, although the molecular events associated with this process have not yet been elucidated in grapevine. A next generation RNA sequencing (RNA-Seq) approach was used to study global transcriptional changes associated with resistance induced by T39 in Vitis vinifera Pinot Noir leaves. The long-term aim was to develop strategies to optimize the use of this agent for downy mildew control. More than 14.8 million paired-end reads were obtained for each biological replicate of T39-treated and control leaf samples collected before and 24 h after P. viticola inoculation. RNA-Seq analysis resulted in the identification of 7,024 differentially expressed genes, highlighting the complex transcriptional reprogramming of grapevine leaves during resistance induction and in response to pathogen inoculation. Our data show that T39 has a dual effect: it directly modulates genes related to the microbial recognition machinery, and it enhances the expression of defence-related processes after pathogen inoculation. Whereas several genes were commonly affected by P. viticola in control and T39-treated plants, opposing modulation of genes related to responses to stress and protein metabolism was found. T39-induced resistance partially inhibited some disease-related processes and specifically activated defence responses after P. viticola inoculation, causing a significant reduction of downy mildew symptoms. The global transcriptional analysis revealed that defence processes known to be implicated in the reaction of resistant genotypes to downy mildew were partially activated by T39-induced resistance in susceptible grapevines. Genes identified in this work are an important source of markers for selecting novel resistance inducers and for the analysis of environmental conditions that might affect induced resistance mechanisms.

Separation and identification of volatile compounds from liquid cultures of Trichoderma harzianum by GC-MS using three different capillary columns.

Abstract: A simple, fast, repeatable and less laborious sample preparation protocol was developed and applied for the analysis of biocontrol fungus Trichoderma harzianum strain FA1132 by using gas chromatography-mass spectrometry. The match factors for sample spectra with respect to the mass spectra library of fungal volatile compounds were determined and used to study the complex hydrocarbons and other volatile compounds, which were separated by using different capillary columns with nonpolar, medium polar and high polar stationary phases. To date, more than 278 volatile compounds (with spectral match factor at least 90%) such as normal saturated hydrocarbons (C7-C30), cyclohexane, cyclopentane, fatty acids, alcohols, esters, sulfur-containing compounds, simple pyrane and benzene derivatives have been identified. Most of these compounds have not previously been reported. The method described in this paper is a more convenient research tool for the detection of volatile compounds from the cultures of T. harzianum.

Trichoderma-Enriched Biofertilizer Enhances Production and Nutritional Quality of Tomato (Lycopersicon esculentum Mill.) and Minimizes NPK Fertilizer Use

Abstract: Effective biofertilizer reduces not only the load of chemical fertilizers in crop production but also minimizes the pollution by excessive uses of the latter. The impact of Trichoderma-enriched biofertilizer (BioF), i.e., BioF/compost (household/kitchen wastes composted by Trichoderma harzianum T22) and BioF/liquid (T. harzianum T22 grown in liquid media, i.e., broth culture) were evaluated to recognize their roles in growth, yield and nutritional quality of tomato (Lycopersicon esculentum Mill.) in field studies. Encouraging responses were monitored in all respects. Above 200 and 336.5 % yield increase were recorded over control by BioF/compost alone (T3) and its combination with N:P:K (Nitrogen:Phosphorus:Potassium) application (T4), respectively. Application of 50 % BioF/compost and 50 % BioF/liquid with 50 % N:P:K, provided statistically similar and significant (P ≤ 0.05) performance over control but not significant with standard dose of N:P:K. Total soluble solids, sugar, ascorbic acid, β-carotene, lycopene, phosphorus and manganese content in tomato were significantly higher when fertilized with BioF/compost. In addition, protein content and some essential minerals were increased in 50 % BioF/compost + 50 % N:P:K treatment. Trichoderma composted kitchen wastes can serve as prospective biofertilizer for improvement in yield and quality of tomato cultivation.

Proteomic analysis of grapevine resistance induced by Trichoderma harzianum T39 reveals specific defence pathways activated against downy mildew

Abstract: Downy mildew is caused by the oomycete Plasmopara viticola and is one of the most serious diseases of grapevine. The beneficial microorganism Trichoderma harzianum T39 (T39) has previously been shown to induce plant-mediated resistance and to reduce the severity of downy mildew in susceptible grapevines. In order to better understand the cellular processes associated with T39-induced resistance, the proteomic and histochemical changes activated by T39 in grapevine were investigated before and 1 day after P. viticola inoculation. A comprehensive proteomic analysis of T39-induced resistance in grapevine was performed using an eight-plex iTRAQ protocol, resulting in the identification and quantification of a total of 800 proteins. Most of the proteins directly affected by T39 were found to be involved in signal transduction, indicating activation of a complete microbial recognition machinery. Moreover, T39-induced resistance was associated with rapid accumulation of reactive oxygen species and callose at infection sites, as well as changes in abundance of proteins involved in response to stress and redox balance, indicating an active defence response to downy mildew. On the other hand, proteins affected by P. viticola in control plants mainly decreased in abundance, possibly reflecting the establishment of a compatible interaction. Finally, the high-throughput iTRAQ protocol allowed de novo peptide sequencing, which will be used to improve annotation of the Vitis vinifera cv. Pinot Noir proteome.

Seed priming with Trichoderma harzianum isolates enhances plant growth and induces resistance against Plasmopara halstedii , an incitant of sunflower downy mildew disease

Abstract: Three rhizosphere fungal isolates viz., PGPFYCM-2, PGPFYCM-8 and PGPFYCM-14 of Trichoderma harzianum, applied as seed treatment to a highly susceptible sunflower cultivar were evaluated for their ability to promote growth and induce resistance in sunflower against downy mildew disease caused by Plasmopara halstedii. Treatment of sunflower seeds with both conidial suspension (1 × 108 spores ml−1) and talc formulations (2.1 × 107 spores g−1) at 8 g kg−1 seeds and 10 g kg−1 seeds, significantly promoted growth and reduced disease incidence under both greenhouse and field conditions. Among the treatments, PGPFYCM-14 (1 × 108 spores ml−1) was highly significant (P = 0.05) in inducing resistance of 63 and 69 %, followed by PGPFYCM-2 which offered 41 and 42 % disease protection under greenhouse and field conditions respectively. Formulation treatments of PGPFYCM-14 also protected the plants significantly (P = 0.05) when compared to the untreated control. There was a significant increase in NPK macronutrients uptake in all the treated plants compared to the untreated control and maximum NPK uptake was observed with PGPFYCM-14 (1 × 108 spores ml−1). Under in vitro conditions, all the tested isolates expressed increase in seed germination and vigour index over the control. Tested plant growth promoting fungal (PGPF) isolates remain significant in enhancing vegetative and reproductive growth parameters, including plant height, early flowering, reduced crop duration, ear head size and crop yield under field conditions when compared to the untreated control.

Biological control of fusarium wilt of tomato by antagonist fungi and cyanobacteria

Abstract: Biological control of Fusarium oxysporum f. sp . lycopersici (FOL) causing wilt disease of tomato was studied in vitro as well as under pot conditions. Dual culture technique showed that Aspergillus niger, Penicillium citrinum, Penicillium sp. and Trichoderma harzianum inhibited the radial colony growth of the test pathogen. Methanol extract of Nostoc linckia and Phormidium autumnale showed moderate and minor zone of inhibition. Maximum seed germination was observed in seeds treated with N. linckia (93%), whereas, T. harzianum, P. autumnale, P. citrinum showed 80% seed germination, while A. niger treated seeds showed 50% germination. Under pot conditions, the plant heights, fresh and dry weight of plants were found to be increased significantly (p ≤ 0.05) in all treatments except in P. autumnale amended soil. Similar results were observed in chlorophyll (a+b) content of treated plants. Maximum control of wilt disease was observed with T. harzianum (44.4%) treated plants as compared to FOL inoculated plants. Whereas, effectiveness of the other antagonists were recorded in the following order: A. niger (35.6%), N. linckia (33.3%), P. citrinum (24.4%), and P. autumnale (0.9 %). Key words : Biological control, fusarium wilt, tomato, antagonist fungi, cyanobacteria

Application of Trichoderma harzianum SQR-T037 bio-organic fertiliser significantly controls Fusarium wilt and affects the microbial communities of continuously cropped soil of cucumber

Abstract: BACKGROUND: The reduction in diversity of the soil microbial community causes the disorder of continuous cropping. The aim of this study was to determine the effects of applying Trichoderma harzianum SQR-T037 bio-organic fertiliser (BIO) on the microbial community in continuously cropped cucumber soil. Four treatments were set: (1) control, where neither seedling nursery soil (N) nor transplanted soil (T) was amended with BIO; (2) N treatment, where nursery soil was amended with BIO (1% w/w) but transplanted soil was not; (3) N + T treatment, where BIO was added to both nursery soil (1% w/w) and transplanted soil (0.5% w/w); (4) uncropped soil, where soil was left uncropped consistently. RESULTS: A disease index of 72.2% was found for the control treatment, while the N and N + T treatments had disease indices of only 25 and 15% respectively. Analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed that the bacterial communities of the N and N + T treatments were similar to those of the uncropped soil but distinct from those of the control soil. The fungal communities of the N and N + T treatments differed from those of both the uncropped soil and the control. CONCLUSION: Addition of BIO to both the nursery soil and the transplanted soil can diversify the microbial community in continuously cropped cucumber soil and thus effectively control Fusarium wilt of cucumber plants. Copyright © 2012 Society of Chemical Industry

Comparative study of Trichoderma gene expression in interactions with tomato plants using high-density oligonucleotide microarrays

Abstract: Trichoderma spp. are widely used as biopesticides and biofertilizers to control diseases and to promote positive physiological responses in plants. In vitro and in vivo assays with Trichoderma harzianum CECT 2413 (T34), Trichoderma virens Gv29-8 (T87) and Trichoderma hamatum IMI 224801 (T7) revealed that these strains affected the growth and development of lateral roots in tomato plants in different ways. The early expression profiles of these Trichoderma strains were studied after 20 h of incubation in the presence of tomato plants, using a high-density oligonucleotide (HDO) microarray, and compared to the profiles in the absence of plants. Out of the total 34 138 Trichoderma probe sets deposited on the microarray, 1077 (3.15 %) showed a significant change of at least 2-fold in expression in the presence of tomato plants. The numbers of probe sets identified in the individual Trichoderma strains were 593 in T. harzianum T34, 336 in T. virens T87 and 94 in T. hamatum T7. Carbohydrate metabolism – the chitin degradation enzymes N-acetylglucosamine-6-phosphate deacetylase, glucosamine-6-phosphate deaminase and chitinase – was the most significantly overrepresented process commonly observed in the three Trichoderma strains in early interactions with tomato plants. Strains T7 and T34, which had similar positive effects on plant development in biological assays, showed a significantly overrepresented hexokinase activity in interaction with tomato. In addition, genes encoding a 40S ribosomal protein and a P23 tumour protein were altered in both these strains.

Secretome analysis of the fungus Trichoderma harzianum grown on cellulose

Abstract: Trichoderma harzianum is a mycoparasitic filamentous fungus that produces and secretes a wide range of extracellular hydrolytic enzymes used in cell wall degradation. Due to its potential in biomass conversion, T. harzianum draws great attention from biofuel and biocontrol industries and research. Here, we report an extensive secretome analysis of T. harzianum. The fungus was grown on cellulose medium, and its secretome was analyzed by a combination of enzymology, 2DE, MALDI-MS and -MS/MS (Autoflex II), and LC-MS/MS (LTQ-Orbitrap XL). A total of 56 proteins were identified using high-resolution MS. Interestingly, although cellulases were found, the major hydrolytic enzymes secreted in the cellulose medium were chitinases and endochitinases, which may reflect the biocontrol feature of T. harzianum. The glycoside hydrolase family, including chitinases (EC 3.2.1.14), endo-N-acetylglucosaminidases (EC 3.2.1.96), hexosaminidases (EC 3.2.1.52), galactosidases (EC 3.2.1.23), xylanases (EC 3.2.1.8), exo-1,3-glucanases (EC 3.2.1.58), endoglucanases (EC 3.2.1.4), xylosidases (EC 3.2.1.37), α-L-arabinofuranosidase (EC 3.2.1.55), N-acetylhexosaminidases (EC 3.2.1.52), and other enzymes represented 51.36% of the total secretome. Few representatives were classified in the protease family (8.90%). Others (17.60%) are mostly intracellular proteins. A considerable part of the secretome was composed of hypothetical proteins (22.14%), probably because of the absence of an annotated T. harzianum genome. The T. harzianum secretome composition highlights the importance of this fungus as a rich source of hydrolytic enzymes for bioconversion and biocontrol applications.

Induction of Resistance in Tomato Plants Against Fusarium Oxysporum F. SP. Lycopersici Mediated Through Salicylic Acid and Trichoderma Harzianum

Abstract: The effect of a soil application of salicylic acid (SA) and a biocontrol agent, Trichoderma harzianum (TH) on the induction of phenolic accumulation content and defense enzymes in tomato plants infected with Fusarium oxysporum f. sp. lycopersici (F. oxys- porum) was investigated. The phenolic content was recorded to be higher in all the treatments viz. F. oxysporum, F. oxysporum + TH, F. oxysporum + SA and F. oxysporum + TH + SA than that of the healthy plants and reached its maximum level in the plants treated with F. oxysporum + TH + SA. Tomato plants treated with different concentrations of SA (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mM) showed significant increases in the activities of both peroxidase and polyphenol oxidase where a prominent enhancement was observed at a 1.5 mM concentration of SA. F. oxysporum infection resulted in the induction of both of the enzyme activities but at a lower level. The activities of both peroxidase and polyphenol oxidase reached their maximum on the 28th day, when the plants were treated with F. oxysporum and SA (1.5 mM). The combined application of SA (1.5 mM) and TH in Fusarium infected tomato plants, also enhanced the activities of both of the enzymes.

Chemical composition and antifungal activity of Matricaria recutita flower essential oil against medically important dermatophytes and soil-borne pathogens.

Abstract: Summary Objective Fungal infections are potential public health threats all over the world. In the present study, effect of Matricaria recutita flower essential oil (EO) was evaluated against medically important dermatophytes and opportunistic saprophytes using microbioassay technique. Materials and methods Flower essential oil (EO) of M. recutita prepared by hydrodistillation was analyzed by gas chromatography/mass spectrometry (GC/MS). The effect of plant EO on the growth of pathogenic dermatophytes and opportunistic saprophytes was assessed using microbioassay technique. In the bioassay, fungi were cultured in 6-well flat-bottom microplates in presence of various concentrations of plant EO (2.5–1000 μg/mL) for 4–10 days at 28 °C. Results A total of 14 compounds were identified in the plant oil by GC/MS accounting for 97.5% of the oil composition. The main compound identified was chamazulene (61.3%) followed by isopropyl hexadecanoate (12.7%), trans-trans-farnesol (6.9%) and E-β-farnesol (5.2%). Growth inhibition for the dermatophytes exposed to serial two-fold concentrations of plant EO (2.5 to 80 μg/mL) was reported in the range of 3.24 to 68.15% for Microsporum gypseum, 24.48 to 100% for M. canis, 11.40 to 96.65% for Trichophyton mentagrophytes, 27.79 to 100% for T. rubrum and 45.73 to 100% for T. tonsurans. M. recutita EO inhibited the growth of opportunistic saprophytes by 3.98 to 64.29% for Aspergillus flavus, 6.38 to 93.62% for A. fumigatus, 3.52 to 89.45% for A. niger, 6.38 to 77.66% for Trichoderma harzianum and 17.41 to 89.41% for Fusarium oxysporum in serial two-fold concentrations of 15.62 to 1000 μg/mL. Conclusion Results of the present study indicate that M. recutita could be considered as a potential candidate for designing effective antifungal formulations suitable for treatment of dermatophytosis and other fungal infections.

Trichoderma spp. from rhizosphere soil and their antagonism against Fusarium sambucinum

Abstract: One hundred and forty six (146) isolates of Trichoderma spp. were obtained from rhizosphere soils of potato plants in the middle areas of Gansu Province, China. By means of dual culture method, they were examined for antagonism against Fusarium sambucinum , which causes potato dry rot. Ten of the isolates were found to be evidently antagonistic to the pathogen. Based on morphological characteristics and molecular analyses, the antagonistic isolates were identified as Trichoderma harzianum Rifai , Trichoderma longibrachiatum Rifai, Trichoderma atroviride Karsten and Trichoderma virens. Among these isolates, D-3-1 (T. longibrachiatum ) showed the strongest inhibition of the growth of Fusarium sambucinum . Key words: Trichoderma , potato, dry rot, biological control, Fusarium sambucinum.

Trichoderma harzianum as a biocontrol agent against Alternaria alternata on tobacco

Abstract: Trichoderma fungi are the most popular agents used in a biological control. Therefore, our aim was to determine an impact of Trichoderma harzianum on the fungus Alternaria alternata - a causing agent of the brown spot disease on tobacco. In vitro analyses were made in several variants of double culture, in order to study the effect of diffusible and volatile metabolites. There was strong reducing effect on the development of A.alternata with various mechanisms of antagonistic influence. The volatile metabolites have also shown reducing effect. Some abnormalities were observed in the pathogen's morphology both in diffusible and volatile metabolites. The strong reducing effect of T. harzianum towards A. alternata can be applied in biological control of this pathogen.

Biocontrol Potential of Root Endophytic Fungi and Trichoderma Species Against Fusarium Wilt of Lentil Under In vitro and Greenhouse Conditions

Abstract: Lentil wilt, caused by Fusarium oxysporum f. sp. lentis is one of the main limiting factors to successful lentil cultivation. Effect of four antagonistic fungi, namely: Piriformospora indica , Sebacina vermifera , Trichoderma viride and Trichoderma harzianum as well as combinations among them were evaluated against Fusarium wilt of lentil. In in vitro experiments, the effect of the antagonistic fungi against the pathogen were evaluated in dual cultures of volatile metabolite and colonization. Results revealed that antagonistic fungi could produce a proper zone of inhibition. In pot culture experiments, two isolates of pathogen were inoculated within three time schedules, namely: 10 days prior to sowing, concomitant with sowing and 10 days past sowing. Seventeen treatments, including two controls and fifteen combinations of antagonistic fungi were employed to inoculate seeds concordant with sowing. Plant height, plant dry weight, root length, root dry weight along with disease severity were assessed at the flowering stage. Maximum plant height and minimum disease severity with regard to the two isolates of pathogen were observed in pots treated with S. vermifera +T. harzianum .