Showing papers on "Trichoderma harzianum published in 2018"
TL;DR: It was found that root exudates (RE), obtained from plants grown in a split-root system and exposed to various biotic and abiotic stress factors, were able to stimulate the growth and act as chemoattractants of the biocontrol fungus.
Abstract: Plant roots release complex mixtures of bioactive molecules, including compounds that affect the activity and modify the composition of the rhizosphere microbiome. In this work, we investigated the initial phase of the interaction between tomato and an effective biocontrol strain of Trichoderma harzianum (T22). We found that root exudates (RE), obtained from plants grown in a split-root system and exposed to various biotic and abiotic stress factors (wounding, salt, pathogen attack), were able to stimulate the growth and act as chemoattractants of the biocontrol fungus. On the other hand, some of the treatments did not result in an enhanced chemotropism on Fusarium oxysporum f. sp. lycopersici, indicating a mechanism that may be selective for nonpathogenic microbes. The involvement of peroxidases and oxylipins, both known to be released by roots in response to stress, was demonstrated by using RE fractions containing these molecules or their commercial purified analogs, testing the effect of an inhibitor, and characterizing the complex pattern of these metabolites released by tomato roots both locally and systemically.
114 citations
TL;DR: The accumulation of steroidal glycoalkaloids in the plant after treatments with either T. harzianum or HA confirmed the complexity of the plant response to beneficial microbes, demonstrating that these microorganisms are also capable of activating the chemical defenses.
Abstract: The present study investigated the transcriptomic and metabolomic changes elicited in tomato plants (Solanum lycopersicum cv Micro-Tom) following treatments with the biocontrol agent T harzianum strain M10 or its secondary metabolite harzianic acid (HA), in the presence or absence of the soil-borne pathogen Rhizoctonia solani Transcriptomic analysis allowed the identification of differentially expressed genes (DEGs) that play a pivotal role in plant growth, development and resistance to biotic stress Overall, the results support the ability of T harzianum M10 to activate defense responses in infected tomato plants We observed an induction of hormone-mediated signaling, as shown by the up-regulation of genes involved in the ethylene and jasmonate (ET/JA) biosynthesis Further, the protective action of T harzianum on the host was revealed by the over-expression of genes able to detoxify cells from reactive oxygen species (ROS) Moreover, the over-expression of genes involved in glycolysis, tricarboxylic acid cycle (TCA) and photosynthesis help to understand how this strain promotes plant growth and development On the other hand, HA treatment also stimulated tomato response to the pathogen by inducing the expression of several genes involved in different defense mechanisms (including protease inhibitors, resistance proteins like CC-NBS-LRR) and activating ET/JA- and salicylic acid (SA)-mediated signaling pathways The accumulation of steroidal glycoalkaloids caused by either T harzianum or purified HA, as determined by metabolomic analysis, confirmed the complexity of the plant response to beneficial microbes in terms of secondary metabolism involved in defense mechanisms against pathogens
94 citations
TL;DR: The colony forming ability by Trichoderma in the soil was dramatically increased, but decreased after some time, which is a useful reference basis for further tests in the field and large scale production trials.
Abstract: Disease suppression in Ganoderma-infected oil palm seedlings treated with a conidial suspension of Trichoderma harzianum FA 1132 was tested in plant house conditions to determine the effectiveness of the fungus as a biocontrol agent. The highest efficacy of control was achieved by treatment right after artificial infection; the total number of infected plants was reduced to give the lowest disease severity index (DSI) value of 5.0%, compared to the infected and non-treated control that had the highest DSI of 70.0%. After conidia suspension of FA 1132 was applied, the colony forming ability by Trichoderma in the soil was dramatically increased, but decreased after some time. Results of the present study are a useful reference basis for further tests in the field and large scale production trials.
75 citations
TL;DR: The findings of the present study provide a detailed insight into the physio-biochemical and molecular processes leading to low temperature tolerance in T. harzianum-inoculated tomato plants.
64 citations
TL;DR: The V76-12 isolate was the most effective treatment tested in reducing leaf spot disease of oil palm seedlings, due to its ability to inhibit mycelial growth in vitro, to reduce disease symptoms in vivo and in natural fields, as well as to enhance PAL, POD and PPO activities in the oil palm.
55 citations
TL;DR: An overview of the use of Trichoderma spp.
Abstract: Fungi of the Trichoderma spp. genus, notably Trichoderma harzianum, are commonly used for biological management of deleterious seed‐ and soil‐borne pathogens. The global biopesticides market is booming with a major share of various commercial formulations of T. harzianum. However, there are some major drawbacks associated with these commercial formulations including short shelf life, low on‐field stability and irregular performance in different agro‐climatic regions. For effectively resolving these issues, new strategies are urgently required for efficient management of pathogens. The present review provides an overview of the use of Trichoderma spp., with special emphasis on T. harzianum, and discusses future trends for biological control. Technologies are described for the microencapsulation of fungi and for the biogenic synthesis of nanoparticles, with the aim of improving the biological control of pathogens and contributing to sustainable agricultural practices. © 2018 Society of Chemical Industry
55 citations
TL;DR: Rec recombinant P6281 (rP6281) expressed in Pichia pastoris significantly inhibited the development of grey mold that causes rotting of apple, orange, and cucumber, indicating that rP 6281 may be developed as an effective anti-mold agent for fruit storage.
54 citations
TL;DR: The positive effects of the combined Trichoderma and compost treatment suggest that it may become an alternative to the phosphorus mineral fertilization and metabolic compounds typical of biotic or abiotic stresses are revealed.
Abstract: The ability of Trichoderma harzianum (strain OMG-08) as plant growth promoting fungus (PGPF), was tested on Zea mays plants grown in soil pots added with different inorganic (triple superphosphate and rock phosphate) and organic (cow and horse manure composts) P fertilizers. The effect of treatments was evaluated by following the variations of plants dry biomass and nutrient content, as well as the metabolic changes in plant leaves by both GC-MS and NMR spectroscopy. A synergic effect was observed in treatments with both composts and fungus inoculation, in which not only plant growth and P uptake were enhanced, but also the expression of different metabolites related to an improved photosynthetic activity. Conversely, the combination of Trichoderma with inorganic fertilizers was less effective and even showed a reduction of plants shoot biomass and N content. The corresponding plant metabolome revealed metabolic compounds typical of biotic or abiotic stresses, which may be attributed to a reduced capacity of inorganic fertilizers to provide a sufficient P availability during plant growth. Our findings also indicate that the molecular composition of compost differentiated the Trichoderma activity in sustaining plant growth. The positive effects of the combined Trichoderma and compost treatment suggest that it may become an alternative to the phosphorus mineral fertilization.
48 citations
TL;DR: Six new terpenes, including one harziane diterpene, were isolated from the culture of Trichoderma harzianum X-5, an endophytic fungus obtained from the marine brown alga Laminaria japonica and exhibited growth inhibition of some marine phytoplankton species.
Abstract: Six new terpenes, including one harziane diterpene, 3R-hydroxy-9R,10R-dihydroharzianone (1), one proharziane diterpene, 11R-methoxy-5,9,13-proharzitrien-3-ol (2), three cyclonerane sesquiterpenes, 11-methoxy-9-cycloneren-3,7-diol (3), 10-cycloneren-3,5,7-triol (4), and methyl 3,7-dihydroxy-15-cycloneranate (5), and one acorane sesquiterpene, 8-acoren-3,11-diol (6), were isolated from the culture of Trichoderma harzianum X-5, an endophytic fungus obtained from the marine brown alga Laminaria japonica. Their structures and relative configurations were established by analysis of 1D/2D NMR, HREIMS, and IR data, and the absolute configurations were assigned on the basis of ECD curves or biogenetic considerations. These terpenes possess four different carbon skeletons, and compound 2, with a rarely occurring bicyclic framework, represents a possible precursor of tetracyclic harzianes. Compounds 1–6 exhibited growth inhibition of some marine phytoplankton species.
45 citations
TL;DR: It is suggested that the potential of microcosm under 1-year field stimulates the whole microbial diversity and favors different beneficial taxa across two seasons.
Abstract: Soil weakness across consecutive cropping fields can be partially explained by the changes in microbial community diversity and structure. Succession patterns and co-occurrence mechanisms of bacteria and fungi, especially beneficial or pathogenic memberships in continuous cropping strawberry fields and their response to edaphic factors remained unclear. In this study, Illumina sequencing of bacterial 16S ribosomal RNA and fungal internal transcribed spacer genes was applied in three time-course (1, 5, and 10 years) fields across spring and winter. Results showed that the richness and diversity of bacterial and fungal communities increased significantly (p < 0.05) in 1-year field and decreased afterwards across two seasons. Network analysis revealed beneficial bacterial and fungal genus (Bacillus and Trichoderma) dominated under 1-year field whereas Fusarium accumulated under 10-year field at either season. Moreover, Trichoderma harzianum and Bacillus subtilis that have been reported to effectively control Fusarium wilt in strawberries accumulated significantly under 1-year field. Canonical correspondence analysis showed that beneficial bacterial Rhodospirillales and Rhizobiales and fungal Glomerales accumulated in 1-year field and their distributions were significantly affected by soil pH, microbial biomass C (MBC), and moisture. On the contrary, fungal pathogenic species Fusarium oxysporum strongly increased under 10-year field at the winter sample and the abundance was positively (p < 0.01) correlated with soil moisture. Our study suggested that the potential of microcosm under 1-year field stimulates the whole microbial diversity and favors different beneficial taxa across two seasons. Soil pH, moisture, and MBC were the most important edaphic factors leading to contrasting beneficial and pathogenic memberships across consecutive strawberry cropping fields.
44 citations
TL;DR: Trichoderma harzianum is the best bioagents against cucurbit soil-borne pathogens and dipping roots with bioagent fungi suspension improve a good interaction pathogen antagonist.
Abstract: Various experiments were carried out to promote biological control under semi-arid ecological conditions. In vitro assay, Aspergillus flavus seemed to be the most effective bioagent against Fusarium oxysporum f. sp. niveum and Fusarium solani f. sp. cucurbitae with mycelial inhibition rate above 50%. Aspergillus flavus, Aspergillus niger, and Aspergillus terreus exhibited an exceptional hyperparasitism against F. oxysporum f. sp. melonis. The mycelial growth of five Macrophomina phaseolina isolates decreased in the presence of Trichoderma harzianum (44.42%). In greenhouse experiments, both A. flavus and A. fumigatus used preventively of melon inoculated with FOM generated the highest damage reduction rate of top and root dry weights (40–42 and 51–52%, respectively) and the lowest disease severity index (DSI). A. flavus was also effective in improving the plant development with the highest shoot (SDW) and root (RDW) dry weight values. Penicillium digitatum, Trichoderma harzianum, and Trichoderma viride treated preventively on watermelon and melon plants inoculated with M. phaseolina decreased the damage of SDW and RDW and DSI. The development rate revealed the growth improvement potential of T. harzianum (watermelon, 15%) and A. flavus (melon, 12%). Watermelon plants inoculated with F. solani f. sp. cucurbitae and treated curatively with Trichoderma erinaceum, T. viride, and A. flavus and other inoculated by F. oxysporum f. sp. niveum and treated by Trichoderma helicum recorded the highest values of growth parameters, similarly for T. erinaceum on melon plants inoculated by F. solani f. sp. cucurbitae. Among all treatments for plants inoculated by F. oxysporum f. sp. melonis, those three bioagents T. viride, T. erinaceum, and A. flavus revealed efficiency in plant growth. Trichoderma harzianum is the best bioagents against cucurbit soil-borne pathogens. Preventive treatment represents an effective strategy. Dipping roots with bioagent fungi suspension improve a good interaction pathogen antagonist.
TL;DR: In vitro and in vivo biocontrol potential of the combined application of Trichoderma harzianum strain Th3 and Pseudomonas fluorescens strain RRb11 against the rice blast pathogen and the fungicide carbendazim was evaluated, suggesting that synergism is a rare event in combined use of BCAs.
Abstract: Combined application of biocontrol agents (BCAs) have been used to exploit their synergistic potential. But the analysis of additive, synergistic and antagonistic effects of BCAs has rarely been explored for the biocontrol of plant diseases. This study was conducted to evaluate in vitro and in vivo biocontrol potential of the combined application of Trichoderma harzianum strain Th3 and Pseudomonas fluorescens strain RRb11, and the fungicide carbendazim against the rice blast (RB) pathogen, Magnaporthe oryzae, and the bacterial leaf blight (BLB) pathogen, Xanthomonas oryzae pv. oryzae. Combined application of T. harzianum Th3 and P. fluorescens RRb11 synergistically reduced severity of RB by 69.5% in comparison to the untreated control, displaying a synergy factor (SF) of 1.29. P. fluorescens RRb 11 alone and in combination with T. harzianum Th3 and the mixture of T. harzianum Th3 + carbendazim was antagonistic (SF = 0.71 and 0.45, respectively). The combined application of T. harzianum Th3 and P. fluorescens RRb 11 also enhanced several rice plant growth and yield parameters. Additive, synergistic or antagonistic effects among the two BCAs were assessed by applying the numerical hypothesis of ‘Bliss Independence’ which suggested that the combined application of the two BCAs was synergistic in reducing RB but antagonistic with respect to BLB. Out of the six combined application interactions for both the diseases only one interaction (T. harzianum Th3 and P. fluorescens RRb11) was synergistic against RB, which suggested that synergism is a rare event in combined use of BCAs.
TL;DR: Differences such as one unique base pair between fungal genomes might influence enzyme-substrate binding sites and alter fungal gene expression responses, explaining the enzymatic activities specific to each species observed in the corresponding extracts.
Abstract: Understanding relationships between genes responsible for enzymatic hydrolysis of cellulose and synergistic reactions is fundamental for improving biomass biodegradation technologies. To reveal synergistic reactions, the transcriptome, exoproteome, and enzymatic activities of extracts from Trichoderma harzianum, Trichoderma reesei and Trichoderma atroviride under biodegradation conditions were examined. This work revealed co-regulatory networks across carbohydrate-active enzyme (CAZy) genes and secreted proteins in extracts. A set of 80 proteins and respective genes that might correspond to a common system for biodegradation from the studied species were evaluated to elucidate new co-regulated genes. Differences such as one unique base pair between fungal genomes might influence enzyme-substrate binding sites and alter fungal gene expression responses, explaining the enzymatic activities specific to each species observed in the corresponding extracts. These differences are also responsible for the different architectures observed in the co-expression networks.
TL;DR: A close inspection of the enzymatic activity of these enzymes surprisingly revealed a marked difference between them despite the sequence similarity, with ThBgl1 has an increased tendency to catalyze transglycosylation reaction whileThBgl2 acts more as a hydrolyzing enzyme.
TL;DR: The genome of a biocontrol strain formerly known as Trichoderma harzianum ITEM 908 is presented, which exhibits both growth promoting capabilities and antagonism against different fungal pathogens, including Fusarium graminearum, Rhizoctonia solani, and the root-knot nematode Meloidogyne incognita.
Abstract: So far, biocontrol agent selection has been performed mainly by time consuming in vitro confrontation tests followed by extensive trials in greenhouse and field. An alternative approach is offered by application of high-throughput techniques, which allow extensive screening and comparison among strains for desired genetic traits. In the genus Trichoderma, the past assignments of particular features or strains to one species need to be reconsidered according to the recent taxonomic revisions. Here we present the genome of a biocontrol strain formerly known as Trichoderma harzianum ITEM 908, which exhibits both growth promoting capabilities and antagonism against different fungal pathogens, including Fusarium graminearum, Rhizoctonia solani, and the root-knot nematode Meloidogyne incognita. By genomic analysis of ITEM 908 we investigated the occurrence and the relevance of genes associated to biocontrol and stress tolerance, providing a basis for future investigation aiming to unravel the complex relationships between genomic endowment and exhibited activities of this strain. The MLST analysis of ITS-TEF1 concatenated datasets reclassified ITEM 908 as T. atrobrunneum, a species recently described within the T. harzianum species complex and phylogenetically close to T. afroharzianum and T. guizhouense. Genomic analysis revealed the presence of a broad range of genes encoding for carbohydrate active enzymes (CAZYmes), proteins involved in secondary metabolites production, peptaboils, epidithiodioxopiperazines and siderophores potentially involved in parasitism, saprophytic degradation as well as in biocontrol and antagonistic activities. This abundance is comparable to other Trichoderma spp. in the T. harzianum species complex, but broader than in other biocontrol species and in the species T. reesei, known for its industrial application in cellulase production. Comparative analysis also demonstrated similar genomic organization of major secondary metabolites clusters, as in other Trichoderma species. Reported data provide a contribution to a deeper understanding of the mode of action and identification of activity-specific genetic markers useful for selection and improvement of biocontrol strains. This work will also enlarge the availability of genomic data to perform comparative studies with the aim to correlate phenotypic differences with genetic diversity of Trichoderma species.
TL;DR: In this study it could be successfully proven that T. harzianum as a biological competitor is an effective complement to the use of fungicides.
TL;DR: The role of cellulase from Trichoderma harzianum strain Th22 in stimulation of 2,4-Dihydroxy-7-methoxy-2H-1, 4-benzoxazin-3(4H)-one (DIMBOA) and defense-related gene expressions in maize root against deoxynivalenol producing Fusarium graminearum (FG) by in vitro, in planta and virtual molecular modeling experiments as mentioned in this paper.
TL;DR: The present work has found that Mordant orange-1 were initially degraded by T. harzianum RY44 to benzoic acid and finally transformed into salicylic acid, which strongly enhance the decolorization efficiency.
Abstract: Herein, we systematically reported the capability of T. harzianum RY44 for decolorization of Mordant orange-1. The fungi strains were isolated from the Universiti Teknologi Malaysia tropical rain forest. For initial screening, the decolorization was conducted using 50 strains of the fungi for 20 days incubation time and the best performance was selected. Then, the decolorization capability and fungal biomass were evaluated using different dye concentrations, namely, 0, 50, 75 and 100 ppm. Effects of the carbon sources (fructose, glucose, and galactose), nitrogen sources (ammonium nitrate, ammonium sulfate and yeast extract), surfactant (tween 80), aromatic compounds (benzoic acid, catechol and salicylic acid), and pH on the decolorization efficiency were examined. This study has found that the employed carbon sources, nitrogen sources, and aromatic compounds strongly enhance the decolorization efficiency. In addition, increasing the surfactant volume and pH generally decreased the decolorization efficiencies from 19.5 to 9.0% and 81.7 to 60.5%, respectively. In the mechanism philosophy, the present work has found that Mordant orange-1 were initially degraded by T. harzianum RY44 to benzoic acid and finally transformed into salicylic acid.
TL;DR: Based on morphological and cultural criteria, as well as sequence information and phylogenetic analysis, these isolates could be identified and designated as Penicillium brevicombactum MERVA5, Arthrinium arundinis MERVA22, Diaporthe rudis MERVA25, Aspergillus versicolor MERVA29, Auxarthron alboluteumMERVA32, Dothiorella sarmentorum MERVA34, Lophiost
Abstract: Forty-four endophytic fungal isolates obtained from marine sponge, Hyrtios erectus, were evaluated and screened for their hydrolase activities. Most of the isolates were found to be prolific producers of hydrolytic enzymes. Only 11 isolates exhibited maximum cellular contents of lipids, rhamnolipids, and protein in the fungal isolates under the isolation numbers MERVA5, MERVA22, MERVA25, MERVA29, MERVA32, MERVA34, MERV36, MERVA39, MERVA42, MERVA43, and MERVA44. These isolate extracts exhibit the highest reducing activities against carbohydrate-metabolizing enzymes including α-amylase, α-glucosidase, β-glucosidase, β-glucuronidase, and tyrosinase. Consequently, based on morphological and cultural criteria, as well as sequence information and phylogenetic analysis, these isolates could be identified and designated as Penicillium brevicombactum MERVA5, Arthrinium arundinis MERVA22, Diaporthe rudis MERVA25, Aspergillus versicolor MERVA29, Auxarthron alboluteum MERVA32, Dothiorella sarmentorum MERVA34, Lophiostoma sp. MERVA36, Fusarium oxysporum MERVA39, Penicillium chrysogenum MERVA42, Penicillium polonicum MERVA43, and Trichoderma harzianum MERVA44. The endophytic fungal species, D. rudis MERVA25, P. polonicum MERVA43, Lophiostoma sp. MERVA36, A. alboluteum MERVA32, T. harzianum MERVA44, F. oxysporum MERVA39, A. versicolor MERVA29, and P. chrysogenum MERVA42 extracts, showed significant hepatitis C virus (HCV) inhibition. Moreover, D. sarmentorum MERVA34, P. polonicum MERVA43, and T. harzianum MERVA44 extracts have the highest antitumor activity against human hepatocellular carcinoma cells (HepG2).
TL;DR: Considering the robust nature and diverse production of these catalytic enzymes by these strains, they can be exploited for various bioremediation technologies as well as other biotechnological applications.
TL;DR: It is hypothesized that the combination of loop motifs is the main determinant for the observed differences in Cel7A activity on cellulosic substrates and fine-tuning of the loop flexibility appears to be an important evolutionary target in Trichoderma spp.
Abstract: The ascomycete fungus Trichoderma reesei is the predominant source of enzymes for industrial conversion of lignocellulose. Its glycoside hydrolase family 7 cellobiohydrolase (GH7 CBH) TreCel7A constitutes nearly half of the enzyme cocktail by weight and is the major workhorse in the cellulose hydrolysis process. The orthologs from Trichoderma atroviride (TatCel7A) and Trichoderma harzianum (ThaCel7A) show high sequence identity with TreCel7A, ~ 80%, and represent naturally evolved combinations of cellulose-binding tunnel-enclosing loop motifs, which have been suggested to influence intrinsic cellobiohydrolase properties, such as endo-initiation, processivity, and off-rate. The TatCel7A, ThaCel7A, and TreCel7A enzymes were characterized for comparison of function. The catalytic domain of TatCel7A was crystallized, and two structures were determined: without ligand and with thio-cellotriose in the active site. Initial hydrolysis of bacterial cellulose was faster with TatCel7A than either ThaCel7A or TreCel7A. In synergistic saccharification of pretreated corn stover, both TatCel7A and ThaCel7A were more efficient than TreCel7A, although TatCel7A was more sensitive to thermal inactivation. Structural analyses and molecular dynamics (MD) simulations were performed to elucidate important structure/function correlations. Moreover, reverse conservation analysis (RCA) of sequence diversity revealed divergent regions of interest located outside the cellulose-binding tunnel of Trichoderma spp. GH7 CBHs. We hypothesize that the combination of loop motifs is the main determinant for the observed differences in Cel7A activity on cellulosic substrates. Fine-tuning of the loop flexibility appears to be an important evolutionary target in Trichoderma spp., a conclusion supported by the RCA data. Our results indicate that, for industrial use, it would be beneficial to combine loop motifs from TatCel7A with the thermostability features of TreCel7A. Furthermore, one region implicated in thermal unfolding is suggested as a primary target for protein engineering.
TL;DR: Results of preliminary antagonistic assay reveal that, using the bio-agents Trichoderma harzianum and Glomus versiforme inhibited the cowpea pathogen Erysiphe flexuosa.
TL;DR: Interestingly, it was found that the enriched functional metagenomic signatures on phytoremediation such as benzoate transport and degradation, and degradation of heterocyclic aromatic compounds in the treatment influenced the rhizosphere micro ecosystem favoring growth and health of pepper plant.
TL;DR: Ameliorative effects of Trichoderma harzianum (Th-6) on monocot crops under saline environment using hydroponic system were examined in this paper.
Abstract: Ameliorative effects of Trichoderma harzianum (Th-6) on monocot crops under saline environment using hydroponic system were examined. Both rice and maize seeds were coated with T. harzianum (Th-6) and used for the saline and non-saline treatment. Germination and seedling growth performance were studied. T. harzianum (Th-6)-treated seeds showed constantly faster and more uniform germination as compared to untreated seeds. Moreover, seeds treated with Trichoderma improved plants’ growth and physiological performance under hydroponic saline environment compared to control. The treatments showed higher relative water content (RWC), dark-adapted quantum yield (F
v/F
m ratio), performance index (PIABS), photochemical quenching (q
P), stomatal conductance (g
s), pigments concentrations and antioxidant enzymes as compared to untreated saline environment. Application of endophyte inhibited the Na+ and Cl− ion uptake in leaves when plants were exposed to saline environment. However, H2O2 contents of both treated crops declined under hydroponic salt stress environment. Physiological mechanism of T. harzianum (Th-6) application in mitigating the salt-related consequences of both monocot crops was discussed.
TL;DR: The results suggest an augmented elicitation of natural antioxidant properties in tomato treated with EGTHB-SMS, resulting in a higher radical scavenging activity, that is highly desirable for human health.
Abstract: The present investigation was aimed at evaluating the impact of earthworm grazed and Trichoderma harzianum biofortified spent mushroom substrate (SMS) on natural antioxidant and nutritional properties of tomato. Results of the investigation reveal that earthworm grazing and T. harzianum bio-fortification led to significant improvement in the physico-chemical properties of fresh SMS and its application increased the accumulation of natural antioxidants and mineral content in tomato as compared to either T. harzianum biofortified SMS or fresh SMS. In particular, the earthworm grazed, T. harzianum biofortified SMS (EGTHB-SMS) was found to inhibit lipid peroxidation and protein oxidation with significant increase in total polyphenol and flavonoid content in tomato. Further, it increased Fe2+/Fe3+ chelating activity, superoxide anion radical scavenging activity compared to other treatments. The results thus suggest an augmented elicitation of natural antioxidant properties in tomato treated with EGTHB-SMS, resulting in a higher radical scavenging activity, that is highly desirable for human health. In addition, the use of SMS to enhance the nutritional value of tomato fruits becomes an environment friendly approach in sustainable crop production.
TL;DR: The mixture of antagonists increased the effectiveness of B. subtilis MF352017 (Bs1) isolate on Fusarium wilt and improved chickpea growth, leading to increased plant height, root length, and dry weights of shoot and root.
Abstract: Fusarium wilt is caused by F. oxysporum Schlecht end. Fr. f. sp. ciceris (FOC) is a devastating disease of chickpea in Algeria. In this study, antagonistic effects of B. subtilis MF352017 (Bs1) and Trichoderma harzianum KX523899 (T5) isolated from the rhizosphere of chickpea were investigated separately and in combination for their efficacy in controlling the disease in vivo. The efficacy of the antagonistic biocontrol agents on Fusarium wilt was evaluated based on vegetative and root growth parameters of chickpea. Seed bacterisation with B. subtilis MF352017 (Bs1) and seed treatment with T. harzianum (T5) significantly protected chickpea seedlings from FOC as compared to untreated plants. Plant protection was more pronounced in T. harzianum-treated plants than in bacterised plants. The application of both antagonists effectively suppressed 93.67% of the disease and also enhanced plant growth leading to increased plant height, root length, fresh and dry weights of shoot and root. The mixture of an...
TL;DR: This study revealed for the first time the antagonistic effect of P. putida against M. graminicola, as an endophyte, and application of Pseudomonas putida provided better control of root-knot disease, compared to rest of BCAs.
TL;DR: Evaluation of the deduced amino acid sequence and phylogenetic analysis indicated that ThPV1 is a new member of the genus Betapartitivirus in the family Partitiviridae.
Abstract: We have reported 15 agarose gel band patterns of double-stranded RNA (dsRNA) from Trichoderma spp. We describe herein that band pattern IX in Trichoderma harzianum NFCF319, which appeared to be a single band but consisted of two dsRNAs of similar size, was identified as a novel mycovirus, designated Trichoderma harzianum partitivirus 1 (ThPV1). The larger segment (dsRNA1) of the ThPV1 genome comprised 2,289 bp and contained a single open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRp). The smaller segment (dsRNA2) consisted of 2,245 bp with a single ORF encoding a capsid protein (CP). Evaluation of the deduced amino acid sequence and phylogenetic analysis indicated that ThPV1 is a new member of the genus Betapartitivirus in the family Partitiviridae. Curing of virus infection by single-sporing generated 31 virus-free single-spore clones. No significant differences in growth rate, conidia production, or pigmentation were observed between ThPV1-infected and -cured isogenic strains. In addition, comparison of the newly ThPV1-transmitted isolates with their ThPV1-cured parental strain showed no significant difference in colony morphology or pigmentation. However, inhibition of growth in co-cultured Pleurotus ostreatus and Rhizoctonia solani by T. harzianum was increased in ThPV1-containing strains compared with ThPV1-cured isogenic strains. Moreover, β-1,3-glucanase activity was significantly increased in the ThPV1-containing strains. However, no difference in chitinase activity was observed, suggesting that ThPV1 regulates the activity of a specific fungal enzyme.
TL;DR: Overall, the results showed possibility of using the tested bio-agents to control squash powdery mildew disease as an alternative to fungicides’ use that is harmful for human health and polluting the environment.
Abstract: Squash (Cucurbita pepo L.), one of the most important vegetable crops for human nutrition all over the world, is infected by many diseases, particularly powdery mildew caused by Podosphaera xanthii (syn. Sphaerotheca fuliginea), which is considered the most serious disease causing yield losses. This research study was conducted to investigate the role of Bacillus subtilis, Bacillus chitinosporus, Bacillus pumilus, Bacillus megaterium, Bacillus polymexa, Trichoderma harzianum, and Trichoderma viridi on squash leaves infected with P. xanthii under laboratory and greenhouse conditions. Results indicated that all treatments significantly inhibited the conidial germination of P. xanthii than the control. A significant decrease in the disease symptoms, severity, and the area under disease progress curve (AUDPC) was registered in squash plants sprayed with the tested bio-agents, particularly B. subtilis, B. pumilus, and T. harzianum. The activity of defense-related enzymes, i.e., catalase (CAT), peroxidase (POX), and polyphenol oxidase (PPO), were significantly upregulated as results of most treatments. Light and scanning electron microscopic (SEM) investigation showed that the morphological shape of P. xanthii was abnormal and the pathogen growth was limited in bio-agent-treated plants compared to control plants that showed dramatic infection. Bio-agent treatments significantly increased growth and yield attributes of squash plants over control. Overall, the results showed possibility of using the tested bio-agents to control squash powdery mildew disease as an alternative to fungicides’ use that is harmful for human health and polluting the environment.
TL;DR: The production of xylanases by T. harzianum can be performed in this cross-flow stirred SSF bioreactor at rates up to 1.0 rpm, avoiding heat accumulation and damage on metabolic activity.