Project description:Fungal necromass in soil represents the stable carbon pools. While fungi are known to decompose fungal necromass, how fungi decomopose melanin, remains poorly understood. Recently, Trichoderma species was found to be one of the most commonly associated fungi in soil, we have used a relevant fungal species, Trichoderma reesei, to characterized Genes involved in the decomposition of melanized and non-melanized necromass from Hyaloscypha bicolor.
Project description:Trichoderma species can stimulate local and distant immune responses in colonized plant tissues to prevent future pathogenic attacks. Priming of plant defenses is characterized by changes on transcriptional, metabolic, and epigenetic states after stimulus perception. We have previously investigated the transcriptional reprogramming in silk tissues from maize plants inoculated with Trichoderma atroviride and challenged with Fusarium verticillioides (Agostini et al 2019). To better understand about the molecular changes induced by T. atroviride in maize, a proteomic approach was conducted in this instance. Several proteins belonging to different metabolic categories were detected as priming involved proteins. However, we detected a very low correlation with those priming-modulated transcripts suggesting the importance of regulatory events posteriori of transcriptional stage to accomplish the final goal of blocking the pathogen entrance. Specifically, we focused on phenylpropanoid pathway; since we detected several proteins that are upregulated in priming state might explain the cell wall reinforcement and, the increase in the content of flavonoids and lignin in silks of maize plants after induced systemic resistance activation.
Project description:It has long been recognized that species occupy a specific ecological niche within their ecosystem. The ecological niche is defined as the number of conditions and resources that limit species distribution. Within their ecological niche, species do not exist in a single physiological state but in a number of states we call the Natural Operating Range. In this paper we link ecological niche theory to physiological ecology by measuring gene expression levels of collembolans exposed to various natural conditions. The soil-dwelling collembolan Folsomia candida was exposed to 26 natural soils with different soil characteristics (soil type, land use, practice, etc). The animals were exposed for two days and gene expression levels were measured. The main factor found to regulate gene expression was the soil type (sand or clay), in which 18.5% of the measured genes were differentially expressed. Gene Ontology analysis showed animals exposed to sandy soils experience general stress, affecting cell homeostasis and replication. Multivariate analysis linking soil chemical data to gene expression data revealed that soil fertility influences gene expression. Land-use and practice had less influence on gene expression; only forest soils showed a different expression pattern. A variation in gene expression variation analysis showed overall low variance in gene expression. The large difference in response to soil type was caused by the soil physicochemical properties where F. candida experiences clay soils and sandy soils as very different from each other. This collembolan prefers fertile soils with high organic matter content, as soil fertility was found to correlate with gene expression and animals exposed to sandy soils (which, in general, have lower organic matter content) experience more general stress. Finally, we conclude that there is no such thing as a fixed physiological state for animals in their ecological niche and the boundary between the ecological niche and a stressed state depends on the genes/pathways investigated.
Project description:The free-living soil fungus Trichoderma hamatum GD12 is notable amongst other Trichoderma strains in exhibiting both biocontrol and plant growth promotion (PGP) activities, which are coincident with a markedly expanded genome when compared to other characterised biocontrol and PGP isolates. Here, we make direct comparisons of T. hamatum GD12 transcription during PGP, and during antagonism of the root-infecting pathogen Sclerotinia sclerotiorum, in peat-based microcosms. An extensive mRNA-seq analysis sampling six time-points, 1, 2, 4, 7, 10 and 15 days after microcosm establishment revealed dynamic and biphasic signatures in the transcriptional responses of T. hamatum GD12 during Sclerotinia biocontrol and lettuce growth promotion. Functional analysis of differentially expressed genes demonstrated up-regulation of transportation and oxidation-reduction genes during both processes. Sclerotinia biocontrol is most likely mediated by the synthesis and secretion of antifungal compounds. Notably, the biphasic response during biocontrol was further characterised by the expression of a number of uncharacterised GD12 genes, small-secreted cysteine rich proteins and secondary metabolite producing gene clusters. This work demonstrates that T. hamatum GD12 harnesses a reservoir of uncharacterised genes that are actively engaged during effective biological control of a plurivorous plant pathogen.
Project description:Plant-beneficial fungi from the genus Trichoderma (Hypocreales, Ascomycota) can control oomyceteous plant-pathogenic Pythium myriotylum (Peronosporales, Oomycota) and thus serve as bioeffectors for the eco-friendly products of crop protection. However, the underlying mechanisms of microbe-microbe interactions have yet to be fully understood. In this study, we focused on the role of the Trichoderma secretome induced by P. myriotylum mycelia. For this purpose, we selected strains showing strong (T. asperellum, T. atroviride, T. virens), moderate (T. cf. guizhouense, T. reesei), and weak (T. parepimyces) activities, respectively, and cultured with the sterilized P. myriotylum mycelia. Secreted proteins were analyzed using label-free LC-MS/MS, bioinformatic localization prediction, gene ontology (GO) annotation, and ortholog analysis. The exoproteomic analysis quantified proteins in the six Trichoderma spp., suggesting unequal antagonistic mechanisms among the strong and weak strains, respectively, with different proportions of putative cellulases, proteases, redox enzymes, and extracellular proteins of unknown function. Notably, proteolysis-related proteins were abundant, while the abundant proteases tended not to be conserved across the species (i.e., non-orthologous). Putative cellobiohydrolases were detected abundantly in all Trichoderma species except for the weak antagonist T. parepimyces, even though its genome encodes for these proteins. Notably, secretomes of the most potent anti-Pythium bioeffectors tended to have higher endo-cellulase activity. Cellulose and other glucans are major components of the oomycete cell wall, which was partly reflected in the cellulases produced by the Trichoderma species. The varying abundances of orthologous proteins suggested the evolution of differing transcription regulation mechanisms across the Trichoderma genus in response to the ubiquitous presence of Oomycota.
Project description:It has long been recognized that species occupy a specific ecological niche within their ecosystem. The ecological niche is defined as the number of conditions and resources that limit species distribution. Within their ecological niche, species do not exist in a single physiological state but in a number of states we call the Natural Operating Range. In this paper we link ecological niche theory to physiological ecology by measuring gene expression levels of collembolans exposed to various natural conditions. The soil-dwelling collembolan Folsomia candida was exposed to 26 natural soils with different soil characteristics (soil type, land use, practice, etc). The animals were exposed for two days and gene expression levels were measured. The main factor found to regulate gene expression was the soil type (sand or clay), in which 18.5% of the measured genes were differentially expressed. Gene Ontology analysis showed animals exposed to sandy soils experience general stress, affecting cell homeostasis and replication. Multivariate analysis linking soil chemical data to gene expression data revealed that soil fertility influences gene expression. Land-use and practice had less influence on gene expression; only forest soils showed a different expression pattern. A variation in gene expression variation analysis showed overall low variance in gene expression. The large difference in response to soil type was caused by the soil physicochemical properties where F. candida experiences clay soils and sandy soils as very different from each other. This collembolan prefers fertile soils with high organic matter content, as soil fertility was found to correlate with gene expression and animals exposed to sandy soils (which, in general, have lower organic matter content) experience more general stress. Finally, we conclude that there is no such thing as a fixed physiological state for animals in their ecological niche and the boundary between the ecological niche and a stressed state depends on the genes/pathways investigated. Test animals were exposed to 26 natural soils + 2 control soils. 4 biological replicates per soil containing 25 grams of soil and 30 23-day-old animals per replicate, RNA was isolated after two days of exposure. for the micro-array hybridization design we made use of an interwoven loop design. from the four replicates per soil two were labeled with Cy3 and 2 with Cy5. It was made sure that now two replicates of the same soil were ever hybridized against the same soil.
Project description:This SuperSeries is composed of the following subset Series: GSE19832: Trichoderma virens transcript levels during mycoparasitism GSE23382: Trichoderma atroviride transcript levels during mycoparasitism GSE23410: Trichoderma reesei transcript levels during mycoparasitism Refer to individual Series