Query: Trichoderma 2019

title: Evolution and comparative genomics of the most common Trichoderma species
abstract: BackgroundThe growing importance of the ubiquitous fungal genus Trichoderma (Hypocreales, Ascomycota) requires understanding of its biology and evolution. Many Trichoderma species are used as biofertilizers and biofungicides and T. reesei is the model organism for industrial production of cellulolytic enzymes. In addition, some highly opportunistic species devastate mushroom farms and can become pathogens of humans. A comparative analysis of the first three whole genomes revealed mycoparasitism as the innate feature of Trichoderma. However, the evolution of these traits is not yet understood.ResultsWe selected 12 most commonly occurring Trichoderma species and studied the evolution of their genome sequences. Trichoderma evolved in the time of the Cretaceous Palaeogene extinction event 66 15) mya, but the formation of extant sections (Longibrachiatum, Trichoderma) or clades (Harzianum/Virens) happened in Oligocene. The evolution of the Harzianum clade and section Trichoderma was accompanied by significant gene gain, but the ancestor of section Longibrachiatum experienced rapid gene loss. The highest number of genes gained encoded ankyrins, HET domain proteins and transcription factors. We also identified the Trichoderma core genome, completely curated its annotation, investigated several gene families in detail and compared the results to those of other fungi. Eighty percent of those genes for which a function could be predicted were also found in other fungi, but only 67% of those without a predictable function.ConclusionsOur study presents a time scaled pattern of genome evolution in 12 Trichoderma species from three phylogenetically distant clades/sections and a comprehensive analysis of their genes. The data offer insights in the evolution of a mycoparasite towards a generalist.

title: Non Volatile Metabolites from Trichoderma spp.
abstract: The genus Trichoderma is comprised of many common fungi species that are distributed worldwide across many ecosystems. Trichoderma species are well known producers of secondary metabolites with a variety of biological activities. Their potential use as biocontrol agents has been known for many years. Several reviews about metabolites from Trichoderma have been published. These reviews are based on their structural type, biological activity, or fungal origin. In this review, we summarize the secondary metabolites per Trichoderma species and elaborate on approximately 390 non volatile compounds from 20 known species and various unidentified species.

title: Rapid identification of Trichoderma koningiopsis and Trichoderma longibrachiatum using sequence characterized amplified region markers
abstract: Molecular markers enable the detection and classification of fungi isolated from their natural environments. To develop species specific markers for detecting Trichoderma koningiopsis and T. longibrachiatum, the sequence characterized amplified region technique, using 20 inter simple sequence repeat polymerase chain reaction primers, was performed. The two specific markers for amplifying a single unique band consistent with T. koningiopsis and T. longibrachiatum, which were absent with other Trichoderma strains, were successfully identified. These fragments had no meaningful sequence homology with known sequences available in the National Center for Biotechnology Information and TrichOKEY databases. Compared with traditional identification techniques, these markers can facilitate more rapid and less complicated studies of Trichoderma population dynamics and evaluate their establishment after release into agricultural environments.

title: Endophytic strains of Trichoderma increase plants' photosynthetic capability
abstract: The world faces two enormous challenges that can be met, at least in part and at low cost, by making certain changes in agricultural practices. There is need to produce enough food and fibre for a growing population in the face of adverse climatic trends, and to remove greenhouse gases to avert the worst consequences of global climate change. Improving photosynthetic efficiency of crop plants can help meet both challenges. Fortuitously, when crop plants' roots are colonized by certain root endophytic fungi in the genus Trichoderma, this induces up regulation of genes and pigments that improve the plants' photosynthesis. Plants under physiological or environmental stress suffer losses in their photosynthetic capability through damage to photosystems and other cellular processes caused by reactive oxygen species (ROS) But certain Trichoderma strains activate biochemical pathways that reduce ROS to less harmful molecules. This and other mechanisms described here make plants more resistant to biotic and abiotic stresses. The net effect of these fungi's residence in plants is to induce greater shoot and root growth, increasing crop yields, which will raise future food production. Furthermore, if photosynthesis rates are increased, more CO2 will be extracted from the atmosphere, and enhanced plant root growth means that more sequestered C will be transferred to roots and stored in the soil. Reductions in global greenhouse gas levels can be accelerated by giving incentives for climate friendly carbon farming and carbon cap and trade programmes that reward practices transferring carbon from the atmosphere into the soil, also enhancing soil fertility and agricultural production.

title: Trichoderma as a Model to Study Effector Like Molecules
abstract: Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them.

title: Trichoderma Species: Versatile Plant Symbionts.
abstract: Because of the need to provide food for the growing population, agricultural activity is faced with the huge challenge of counteracting the negative effects generated by adverse environmental factors and diseases caused by pathogens on crops, while avoiding environmental pollution due to the excessive use of agrochemicals. The exploitation of biological systems that naturally increase plant vigor, preparing them against biotic and abiotic stressors that also promote their growth and productivity represents a useful and viable strategy to help face these challenges. Fungi from the genus Trichoderma have been widely used in agriculture as biocontrol agents because of their mycoparasitic capacity and ability to improve plant health and protection against phytopathogens, which makes it an excellent plant symbiont. The mechanisms employed by Trichoderma include secretion of effector molecules and secondary metabolites that mediate the beneficial interaction of Trichoderma with plants, providing tolerance to biotic and abiotic stresses. Here we discuss the most recent advances in understanding the mechanisms employed by this opportunistic plant symbiont as biocontrol agent and plant growth promoter. In addition, through genome mining we approached a less explored factor that Trichoderma could be using to become successful plant symbionts, the production of phytohormones auxins, cytokinins, abscisic acid, gibberellins, among others. This approach allowed us to detect sets of genes encoding proteins potentially involved in phytohormone biosynthesis and signaling. We discuss the implications of these findings in the physiology of the fungus and in the establishment of its interaction with plants.

title: Trichoderma: A part of possible answer towards crop residue disposal
abstract: India is one of the leading countries in agricultural production and generate large volume of crop residue. Increasing demand for food grains due to growing population leads to generation of crop residues. Due to lack of proper disposal mechanism of crop residue, farmers burn the residue which release greenhouse gases (GHGs) into the atmosphere, and poses great threat to environment as well as human health. The residue burning causes greater carbon emission and nutrient losses which otherwise incorporated into the soil system may substantially improve the soil biodiversity. Besides several practices of crop residue management, the most feasible method for farmers is incorporation of residue into the soil with the inoculation of microbes. In soil system the ability of microbial community in degrading organic substances is well known. In the early stages of residue decomposition simple substrates like carbohydrates are degraded by bacteria, but in later stages degradation of complex constituents viz. cellulose, lignin needs microbes which are capable of secreting enzymes like cellulase, acting on complex organic substrates. In this context, cellulolytic micro organisms like Trichoderma have the potential and emerging as an important microbial inoculants to enhance the rate of decomposition as well as alleviate the effect of residue burning.

title: Bioactive Volatile Metabolites of Trichoderma: An overview
abstract: Root associated beneficial microbes are potential eco friendly tool and play important role in triggering plant performance against biotic and abiotic stresses. In comparison to chemical based practices, the fungi such as Trichoderma which are also explored as biocontrol agents are promising and sustainable solution for managing plant diseases. The molecular arsenal of these biocontrol attributes including secretion of volatile and nonvolatile compounds which either alone or in combination with other metabolites is responsible for inhibiting phytopathogens and promoting health of the associated host. Till date, a number of volatile organic compounds (VOCs) of diverse chemical nature have been characterized from Trichoderma spp. These metabolites of Trichoderma are of vital importance in agricultural, food, and pharmaceutical applications. The VOCs of compounds are known to play diverse functions both in above and underground part of an ecosystem. The widely recognized molecular role of VOCs includes mediators of inter colony communication, warning signals, pest management, and nutrient acquisitions through root architecture adjustment. The volatile bioactive metabolites such as 6 pentyl a pyrone are known to exhibit multiple actions such as inhibiting growth of fungal mycelium, spore germination, and pigmentation of plant pathogenic fungi. Here, an attempt has been made to discuss bioactive volatile metabolites of Trichoderma origin and their role in combating both biotic and abiotic stress responses of host plants.

title: Trichoderma Histone Deacetylase HDA 2 Modulates Multiple Responses in Arabidopsis1
abstract: HDA 2 histone deacetylase plays a pivotal role in the symbiont fungus Trichoderma atroviride by modulating multiple responses to establish a symbiotic relationship. Trichoderma spp. are a rich source of secondary metabolites and volatile organic compounds (VOCs) which may induce plant defenses and modulate plant growth. In filamentous fungi, chromatin modifications regulate secondary metabolism. In this study we investigated how the absence of histone deacetylase HDA 2 in the Trichoderma atroviride strain Dhda 2 impacts its effect on a host, Arabidopsis (Arabidopsis thaliana) The production of VOCs and their impact on plant growth and development were assessed as well. The Dhda 2 strain was impaired in its ability to colonize Arabidopsis roots, thus affecting the promotion of plant growth and modulation of plant defenses against foliar pathogens Botrytis cinerea and Pseudomonas syringae, which normally result from interaction with T. atroviride. Furthermore, Dhda 2 VOCs were incapable of triggering plant defenses to counterattack foliar pathogens. The Dhda 2 overproduced the VOC 6 pentyl 2H pyran 2 one (6 PP) which resulted in enhanced root branching and differentially regulated phytohormone related genes. Analysis of ten VOCs (including 6 PP) revealed that three of them positively regulated plant growth, whereas six had the opposite effect. Assessment of secondary metabolites, detoxification, and communication with plant related genes showed a dual role for HDA 2 in T. atroviride gene expression regulation during its interaction with plants. Chromatin immunoprecipitation of acetylated histone H3 on the promoters of plant responsive genes in Dhda 2 showed, in the presence of Arabidopsis, low levels of epl 1 and abc 2 compared with that in the wild type; whereas ctf 1 presented high constitutive levels, supporting a dual role of HDA 2 in gene regulation. This work highlights the importance of HDA 2 as a global regulator in Trichoderma to modulate multiple responses in Arabidopsis.

title: Trichoderma Species Differ in Their Volatile Profiles and in Antagonism Toward Ectomycorrhiza Laccaria bicolor
abstract: Fungi of the genus Trichoderma are economically important due to their plant growth and performance promoting effects, such as improved nutrient supply, mycoparasitism of plant pathogens and priming of plant defense. Due to their mycotrophic lifestyle, however, they might also be antagonistic to other plant beneficial fungi, such as mycorrhiza forming species. Trichoderma spp. release a high diversity of volatile organic compounds (VOCs) which likely play a decisive role in the inter species communication. It has been shown that Trichoderma VOCs can inhibit growth of some plant pathogens, but their inhibition potentials during early interactions with mutualistic fungi remain unknown. Laccaria bicolor is a common ectomycorrhizal fungus which in symbiotic relationship is well known to facilitate plant performance. Here, we investigated the VOC profiles of three strains of Trichoderma species, Trichoderma harzianum, Trichoderma Hamatum, and Trichoderma velutinum, as well as L. bicolor by stir bar sorptive extraction and gas chromatography mass spectrometry (SBSE GC MS) We further examined the fungal performance and the VOC emission profiles during confrontation of the Trichoderma species with L. bicolor in different co cultivation scenarios. The VOC profiles of the three Trichoderma species were highly species dependent. T. harzianum was the strongest VOC emitter with the most diverse compound pattern, followed by T. hamatum and T. velutinum. Co cultivation of Trichoderma spp. and L. bicolor altered the VOC emission patterns dramatically in some scenarios. The co cultivations also revealed contact degree dependent inhibition of one of the fungal partners. Trichoderma growth was at least partially inhibited when sharing the same headspace with L. bicolor. In direct contact between both mycelia, however, L. bicolor growth was impaired, indicating that Trichoderma and L. bicolor apply different effectors when defending their territory. Multivariate analysis demonstrated that all examined individual fungal species in axenic cultures, as well as their co cultivations were characterized by a distinct VOC emission pattern. The results underline the importance of VOCs in fungal interactions and reveal unexpected adjustability of the VOC emissions according to the specific biotic environments.