Project description:In this study, we explored the genes involved with the host communication and colonization process through transcriptomic profiling of Trichoderma virens as it colonizes hydroponic maize roots, compared to the fungus without roots present.
Project description:Combating the action of plant pathogenic microorganisms by antagonistic or mycoparasitic fungi has been announced as an attractive biological alternative to the use of chemical fungicides since more than 20 years, and gains additional importance in current trends to environmentally friendly agriculture. Taxa of the fungal genus Hypocrea/Trichoderma (Ascomycota, Hypocreales, Hypocreaceae) contain prominent examples of such biocontrol agents, because they not only antagonize plant-pathogenic fungi, but are also often rhizosphere competent and can enhance plant growth. Identification of the primary factors that regulate the mycoparasitic behaviour and metabolic activities related to it will therefore allow the full ecological significance of this trait to be explored. We performed the analysis of the genome sequence from two mycoparasitic and rhizosphere competent Trichoderma spp. – T. atroviride and T. virens – and compare it to that of the saprophyte T. reesei. The predicted gene inventory of the T. atroviride and T.virens genome, therefore, points to previously unknown mechanisms operating during biocontrol of plant pathogens. The availability of these genomes provides a unique opportunity to develop a deeper understanding of the processes fundamental to mycoparasitism and its application for the breeding of improved biocontrol strains for plant protection. To investigate the potential role in mycoparasitism, microarrays were used to examine T. virens transcript levels when confronted with a potential prey (the plant pathogen Rhizoctonia solani) before contact, during first physical contact and during overgrowth of the host. The study presented here is the result of this analysis. Two biological pools by condition against a common reference control each sample hybridized in dye switch. On the two biological replicates we apply on the pretreated results the linear modeling approach implemented by lmFit and the empirical Bayes statistics implemented by eBayes from the limma R package (Smyth 2004). For mycoparasitism confrontation assays T. virens was grown on potato dextrose agar plates (BD Dicfo, Franklin Lakes, NJ, USA), covered with cellophane, in constant light at 25°C and harvested when the mycelia were ca. 5 mm apart (before contact), at contact of the mycelia and after T. virens had overgrown the host fungus Rhizoctonia solani by ca. 5 mm (after contact). As control T. virens was confronted with itself and harvested at contact. Peripheral hyphal zones from each confrontation stage were harvested and shock frozen in liquid nitrogen. Mycelia were ground to a fine powder under liquid nitrogen and total RNA was isolated using the guanidinium thiocyanate method (Sambrook, 2001).
Project description:To test the hypothesis that gene expression by the fungal partner in this beneficial interaction is modulated by the plant host, Trichoderma virens was co-cultured with maize or tomato in a hydroponic system allowing interaction with the roots. The transcriptomes for T. virens alone were compared with fungus-inoculated tomato or maize roots by hybridization on oligonucleotide microarrays Based on the relevant role of Trichoderma virens as a biological control agent this study provides a better knowledge of its crosstalk with plants in a host-specific manner. Trichoderma virens was co-cultured for three days with maize or tomato in a hydroponic system allowing interaction with the roots. 3 experiments were performed for each treatment, and compared to 5 experiments with T. virens grown under the same conditions without plants.
Project description:To test the hypothesis that gene expression by the fungal partner in this beneficial interaction is modulated by the plant host, Trichoderma virens was co-cultured with maize or tomato in a hydroponic system allowing interaction with the roots. The transcriptomes for T. virens alone were compared with fungus-inoculated tomato or maize roots by hybridization on oligonucleotide microarrays Based on the relevant role of Trichoderma virens as a biological control agent this study provides a better knowledge of its crosstalk with plants in a host-specific manner.
Project description:A Trichoderma microarrays composed of 385,000 probes, designed against the genomes of Trichoderma reesei (= Hypocrea jecorina), ID: 431241 (9,129 genes) + Trichoderma virens (= Hypocrea virens), ID: 413071 (11,643 genes) + Trichoderma atroviride (= Hypocrea atroviridis) ID: 197014A (11,643 genes), was constructed (Roche-NimbleGen, Inc., Madison, WI, USA). Probes contained entere transcript sequence. This microarray was used to analyze the transcriptomic changes of T. atroviride IMI 352941 (T11) in three conditions: T11 growing alone, T11 growing at ca 5 mm of V. dahliae V-138I and T11 overgrowing V-138I.
Project description:Hypocrea jecorina (anamorph Trichoderma reesei) is one of the most well studied fungi used in biotechnology industry. This fungus is today a paradigm for the comercial scale production of different plant cell wall degrading enzymes, mainly cellulases and hemicellulases. The objective of this study was to analyze the transcriptional profiling of T. reesei (Δxyr1) grown in presence of cellulose, sophorose and glucose as the carbon source using RNA-seq approach.
Project description:Combating the action of plant pathogenic microorganisms by antagonistic or mycoparasitic fungi has been announced as an attractive biological alternative to the use of chemical fungicides since more than 20 years, and gains additional importance in current trends to environmentally friendly agriculture. Taxa of the fungal genus Hypocrea/Trichoderma (Ascomycota, Hypocreales, Hypocreaceae) contain prominent examples of such biocontrol agents, because they not only antagonize plant-pathogenic fungi, but are also often rhizosphere competent and can enhance plant growth. Identification of the primary factors that regulate the mycoparasitic behaviour and metabolic activities related to it will therefore allow the full ecological significance of this trait to be explored. We performed the analysis of the genome sequence from two mycoparasitic and rhizosphere competent Trichoderma spp. – T. atroviride and T. virens – and compare it to that of the saprophyte T. reesei. The predicted gene inventory of the T. atroviride and T.virens genome, therefore, points to previously unknown mechanisms operating during biocontrol of plant pathogens. The availability of these genomes provides a unique opportunity to develop a deeper understanding of the processes fundamental to mycoparasitism and its application for the breeding of improved biocontrol strains for plant protection. To investigate the potential role in mycoparasitism, microarrays were used to examine T. virens transcript levels when confronted with a potential prey (the plant pathogen Rhizoctonia solani) before contact, during first physical contact and during overgrowth of the host. The study presented here is the result of this analysis.
Project description:Trichoderma spp. are filamentous fungi that colonize plant roots conferring beneficial effects to plants, indirectly through the induction of their defense systems or directly through the suppression of phytopathogens in the rhizosphere. Transcriptomic analyses of Trichoderma emerged as a powerful method for identifying the molecular events underlying the establishment of this beneficial relationship. Here, we focus on the transcriptomic response of Trichoderma virens during its interaction with Arabidopsis seedlings. The main response of T. virens to co-cultivation with Arabidopsis was the repression of gene expression. The biological processes of transport and metabolism of carbohydrates were downregulated, including a set of cell-wall-degrading enzymes putatively relevant for root-colonization. Repression of such genes reached their basal levels at later times of the interaction when genes belonging to the biological process of copper ion transport were induced, a necessary process providing copper as a cofactor for cell-wall degrading enzymes with auxiliary activities (AAs) class. RNA-Seq analysis showed the induction of a member of the SNF2 family of chromatin remodelers/helicase-related proteins, which was named IPA-1 (Increased Protection of Arabidopsis-1). Sequence analyses of IPA-1 showed as its closest relatives members of the Rad5/Rad16- and SNF2-subfamilies; however, it grouped into a different clade. Although deletion of ipa-1 in T. virens did not affect its growth, the antibiosis of Δipa-1 culture filtrates showed a diminished effect against Rhizoctonia solani but remained unaltered against Botrytis cinerea. Triggering of the plant defense genes in plants treated with Δipa-1 was higher, showing enhanced resistance against Pseudomonas syringae but not against B. cinerea as compared to wild type.
Project description:The identification and characterization of the transcriptional regulatory networks governing the physiological behaviour and adaptation of microbial cells is a key step in understanding their behaviour. One such wide-domain regulatory circuit, essential to all cells, is carbon catabolite repression (CCR): it allows the cell to prefer some carbon sources, whose assimilation is of high nutritional value, over less profitable ones. This system has been investigated in bacteria, yeast and filamentous fungi. In the latter, the C2H2 zinc finger protein has been shown to act as the central transcriptional repressor in this process. Here, we deciphered the CRE1 regulon by profiling transcription in a wild-type and delta-cre1 mutant strains on glucose in the model cellulose and hemicellulose-degrading fungus Trichoderma reesei (anamorph of Hypocrea jecorina) at constant growth rates known to per se repress and derepress CCR-affected genes.
Project description:Filamentous fungus (anamorph: Trichoderma reesei; teleomorph: Hypocrea jecorina) important to industry for its cellulase production