In-vitro Competition Bio-assay Experiment on the Effect of Trichoderma Species and Some Crop Pathogenic Fungi

Fungi of the genus Trichoderma have a track record of being antagonist to quite of a number of agricultural important pathogens. Trichoderma have some unique characteristics that make it scientifically proven and suitable bio-control agents against varieties of pathogenic organism infecting economic food crops. Trichoderma has the advantage of being environment friendly and not hazardous to the health of human beings, livestock, soil and environment. Competitive bio-assay experiment was carried out in the laboratory on the effects of Trichoderma species (T. atroviride P1 isolates, T. harzianum T22 isolates, T. viride) on some crop pathogens (Phytophthora cinnanerium, Botrytis cinaria and Rhizoctonia solani). Pure culture of Trichoderma and pathogenic fungi were replicated four times and arranged in a complete block design. The result of the experiment shows that Trichoderma species are strong competitor of P. cinnanerium, B. cinaria and R.solani. Within 72 hours, the Trichoderma species were able to grow and completely overlap the P. cinnanerium, B. cinaria and R. solani. This strong competitiveness indicated that Trichoderma species would effectively inhibit the growth of P. cinnanerium, B. cinaria and R. solani on the infected crop; thus the application of Trichoderma species in the control of P. cinnanerium, B. cinariaand R. solani infected crops. Keywords: Trichoderma, bio-control, Phytophthora cinnanerium, Botrytis cinaria, Rhizoctonia solani, pathogens, fungi

Efficacy of Trichoderma harzianum, Poultry manure and Yeast on the Growth and Yield of Soybean Grown on Nematode Infested Soil

Field experiments were carried out during 2010 and 2011 planting seasons in order to assess the effect of Trichoderma harzianum, cured poultry manure and palm wine yeast, singly and in combination, on the growth and yield of soybean, variety TGx 536-02D, grown on nematodes infested soil. The treatments were control, T. harzianum T22 isolate, cured poultry manure, palm wine yeast, T. hazianumT22 isolate + cured poultry manure, T. hazianumT22 isolate + palm wine yeast, cured poultry manure + palm wine yeast and T. hazianumT22 isolate + cured poultry manure + palm wine yeast. Control experiment did not receive cured poultry manure, palm wine yeast or T. hazianumT22 isolate. In each trial, there were 8 treatments replicated 5 times fitted into randomized complete block design. The results indicated that application of T.hazianumT22 isolate, cured poultry manure, palm wine yeast, T. hazianum + cured poultry manure, T. hazianum + palm wine yeast, cured poultry manure + palm wine yeast and T. hazianumT22 isolate + cured poultry manure + palm wine yeast significantly (p<0.05) increased the growth and yield of soybean, and also significantly (p<0.05) reduced the soil population dynamics of nematode pests of soybean. Prominent nematode genera were Meloidogyne, Xiphinema and Helicotylenchus. Control plants that were not treated with palm wine yeast, T. harzianum T22 isolate and cured poultry manure had significantly (p<0.05) reduced the growth and yield of soybean,and had increased soil nematode population. Data collected on both trials were analyzed using analysis of variance and significant differences among treatments were separated using Duncan’s multiple range test at probability level of 5%. Keywords: Trichoderma harzianum; poultry manure; yeast; soybean; control; nematode

Study of proteome pattern of Pseudomonas fluorescens strain UTPF68 in interaction with Trichoderma atroviride strain P1 and tomato

Saprophitic Pseudomonas species are root-colonizing bacteria that can improve plant health. Efficient exploitation of these bacteria in agriculture requires knowledge of traits that enhance ecological performance in the rhizosphere. Some Pseudomonas fluorescens strains present biocontrol properties, protecting the roots of some plant species against plant pathogens. These bacteria induce systemic resistance in the host plant, so it can better resist attack by a true pathogen. The bacteria outcompete other (pathogenic) soil microbes, e.g., by siderophores, giving a competitive advantage at scavenging for iron. The bacteria produce compounds antagonistic to other soil microbes, such as phenazine - type antibiotics or hydrogen cyanide. In this study  the changes in the protein profile of P. fluorescens strain UTPF68, involved in the multiple interactions between plant (tomato) and an antagonistic agent (Trichoderma atroviride strain P1) investigated. Two-dimensional electrophoresis was used to analyze separately collected proteins from each one, two or three partner interactions. The results about differential produced spots in Pseudomonas proteome in each collation, showed that 18 differential spots became visible as new, 16 spots were absent, 17 spots were up-regulated and 1 spot was down-regulated, when Tomato-Pseudomonas (TP) condition was compared with control Pseudomonas alone (P). Also more than 84 differential spots were accumulated in proteome of Pseuodomonas due to the presence of Trichoderma, as new, absent, increased and decreased spots. By comparison of conditions revealed 2 protein spots that detected by MS, have newly expressed in present of Plant and Trichoderma. These proteins corresponded to arginine deiminase of P. putida GB-1 and Chaperonin GroEL protein of P. putida S16 that their expressions associated to stress condition.The results indicated that the presence of Plant and Trichoderma induces major changes in the protein profile of Pseudomonas

Trichoderma and its secondary metabolites improve yield and quality of grapes

Trichoderma is one of the most studied and applied fungal biocontrol agents. The benefits of these microorganisms to the plant include: suppression of pathogens, growth promotion, enhanced nutrient availability and induction of resistance. The biological activity is related to the variety of metabolites that they produce. These metabolites have been found to directly inhibit the pathogens, increase disease resistance and enhance plant growth. In this study, we have examined the effect of two Trichoderma strains and their secondary metabolites on Vitis vinifera in terms of induction of disease resistance, plant growth promotion and increase of polyphenols or antioxidant activity in the grapes. Applications of T. harzianum M10 or T. atroviride P1, as well as their respective major secondary metabolites, harzianic acid (HA) and 6-pentyl-a-pyrone (6PP), have been conducted in greenhouse by foliar spray or drenching. The treatments suppressed the development of powdery mildew caused by Uncinula necator. In a field experiment, a spore suspension of T. harzianum strain T22 or a 6PP solution was applied until fruit harvest. The results indicated that both T. harzianum T22 and 6PP are able to improve crop yield and increase the total amount of polyphenols and antioxidant activity in the grapes. The effects of the isolated natural compounds were comparable with those obtained by using the living fungus

Trichoderma-based products and their widespread use in agriculture

Governing bodies throughout the world, particularly in Europe, are now implementing legislative mandates with the objective of decreasing dependence on pesticides in agriculture to increase consumer and environmental safety. In order to reduce the risks associated with pesticide applications and reduce dependency on their use, Directives will promote low pesticide-input by implementing integrated pest management (IPM), and provide the means to establish the necessary conditions and measures to employ these practices, as well as to ensure security of commercial products. One approach includes the use of biological control agents and their products as alternatives to synthetic agro-chemicals. Trichoderma spp. are widely studied fungi and are among the most commonly used microbial biological control agents (MBCAs) in agriculture. They are presently marketed as bio-pesticides, biofertilizers, growth enhancers and stimulants of natural resistance. The efficacy of this fungus can be attributed to their ability to protect plants, enhance vegetative growth and contain pathogen populations under numerous agricultural conditions, as well as to act as soil amendments/inoculants for improvement of nutrient ability, decomposition and biodegradation. The living fungal spores (active substance) are incorporated in various formulations, both traditional and innovative, for applications as foliar sprays, pre-planting applications to seed or propagation material, post-pruning treatments, incorporation in the soil during seeding or transplant, watering by irrigation or applied as a root drench or dip. Trichoderma-based preparations are marketed worldwide and used for crop protection of various plant pathogens or increase the plant growth and productivity in diverse cultivated environments such as fields, greenhouses, nurseries; in the production of a variety of horticultural, fruits, trees and ornamental crops. A survey was conducted of Trichoderma-containing products found on the international market to obtain an overall perspective of the: 1) geographical distribution, 2) product composition and identity of Trichoderma species selected, 3) contents combined with Trichoderma in the products - other microbial species or substances in the mix, 4) number of products available globally and geographically, 5) number of products registered or having use specifications, 6) product formulations and applications, 7) manufacturer claims - target use, target pests, product type and effects of applications. The largest distribution of Trichoderma bioproducts is found in Asia, succeeded by Europe, South- Central America and North America. The majority of the labels indicated fungicidal properties, but only 38% of the marketed merchandise are registered. Ten Trichoderma species are specifically indicated, but many labels indicate a generic Trichoderma sp. or spp. mix in the list of ingredients. The most common formulation is a wettable powder, followed by granules. Generally, Trichoderma are applied to the seed or propagation material at the time of planting, then the secondary use is during plant development. On the whole, the target use is for the control of soilborne fungal pathogens such as Rhizoctonia, Pythium and Sclerotinia, and a few foliar pathogens such as Botrytis and Alternaria; whereas the minor use indication is for plant growth promotion. The use of Trichoderma-based biological products will have an important role in agricultural production of the future, in light of changing worldwide perspectives by consumers and governing bodies

Polyketide synthases of Diaporthe helianthi and involvement of DhPKS1 in virulence on sunflower

Background The early phases of Diaporthe helianthi pathogenesis on sunflower are characterized by the production of phytotoxins that may play a role in host colonisation. In previous studies, phytotoxins of a polyketidic nature were isolated and purified from culture filtrates of virulent strains of D. helianthi isolated from sunflower. A highly aggressive isolate (7/96) from France contained a gene fragment of a putative nonaketide synthase (lovB) which was conserved in a virulent D. helianthi population. Results In order to investigate the role of polyketide synthases in D. helianthi 7/96, a draft genome of this isolate was examined. We were able to find and phylogenetically analyse 40 genes putatively coding for polyketide synthases (PKSs). Analysis of their domains revealed that most PKS genes of D. helianthi are reducing PKSs, whereas only eight lacked reducing domains. Most of the identified PKSs have orthologs shown to be virulence factors or genetic determinants for toxin production in other pathogenic fungi. One of the genes (DhPKS1) corresponded to the previously cloned D. helianthi lovB gene fragment and clustered with a nonribosomal peptide synthetase (NRPS) -PKS hybrid/lovastatin nonaketide like A. nidulans LovB. We used DhPKS1 as a case study and carried out its disruption through Agrobacterium-mediated transformation in the isolate 7/96. D. helianthi DhPKS1 deleted mutants were less virulent to sunflower compared to the wild type, indicating a role for this gene in the pathogenesis of the fungus. Conclusion The PKS sequences analysed and reported here constitute a new genomic resource that will be useful for further research on the biology, ecology and evolution of D. helianthi and generally of fungal plant pathogens

Multiple roles and effects of a novel Trichoderma hydrophobin

Fungi belonging to the genus Trichoderma are among the most active and ecologically successful microbes found in natural environments, as they are able to use a variety of substrates and affect the growth of other microbes and virtually any plant species. We isolated and characterized a novel type II hydrophobin secreted by the biocontrol strain MK1 of Trichoderma longibrachiatum. The corresponding gene (Hytlo1) has a multiple role in the Trichoderma-plant-pathogen three-way interaction, while the purified protein displayed a direct antifungal as well as a MAMP and a plant growth promotion (PGP) activity. Leaf infiltration with the hydrophobin systemically increased resistance to pathogens and activated defence-related responses involving ROS, SOD, oxylipins, phytoalexins and PR-proteins formation or activity. The hydrophobin was found to enhance development of a variety of plants when applied at very low doses. It particularly stimulated root formation and growth, as demonstrated also by transient expression of the encoding gene in tobacco and tomato. Targeted knock-out of Hytlo1 significantly reduced both antagonistic and PGP effect of the WT strain. We conclude that this protein represents a clear example of a molecular factor developed by Trichoderma to establish a mutually beneficial interaction with the colonized plant

Beauveria bassiana rewires molecular mechanisms related to growth and defense in tomato

Plant roots can exploit beneficial associations with soil-inhabiting microbes, promoting growth and expanding the immune capacity of the host plant. In this work, we aimed to provide new information on changes occurring in tomato interacting with the beneficial fungus Beauveria bassiana. The tomato leaf proteome revealed perturbed molecular pathways during the establishment of the plant–fungus relationship. In the early stages of colonization (5–7 d), proteins related to defense responses to the fungus were down-regulated and proteins related to calcium transport were up-regulated. At later time points (12–19 d after colonization), up-regulation of molecular pathways linked to protein/amino acid turnover and to biosynthesis of energy compounds suggests beneficial interaction enhancing plant growth and development. At the later stage, the profile of leaf hormones and related compounds was also investigated, highlighting up-regulation of those related to plant growth and defense. Finally, B. bassiana colonization was found to improve plant resistance to Botrytis cinerea, impacting plant oxidative damage. Overall, our findings further expand current knowledge on the possible mechanisms underlying the beneficial role of B. bassiana in tomato plants

The Top 10 oomycete pathogens in molecular plant pathology

Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens which threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant-pathogenic oomycete species based on scientific and economic importance. In total, we received 263 votes from 62 scientists in 15 countries for a total of 33 species. The Top 10 species and their ranking are: (1) Phytophthora infestans; (2, tied) Hyaloperonospora arabidopsidis; (2, tied) Phytophthora ramorum; (4) Phytophthora sojae; (5) Phytophthora capsici; (6) Plasmopara viticola; (7) Phytophthora cinnamomi; (8, tied) Phytophthora parasitica; (8, tied) Pythium ultimum; and (10) Albugo candida. This article provides an introduction to these 10 taxa and a snapshot of current research. We hope that the list will serve as a benchmark for future trends in oomycete research.Keywords: microbiology, diversity, genomics, oomycetes plant patholog