Gene expression response of the mycoparasite Trichoderma atroviride to confrontation with the host Rhizoctonia solani in the wild-type and tmk1 gene deletion mutants
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ABSTRACT: Mycoparasitism is a key feature of Trichoderma biocontrol agents. Recent studies of intracellular signal transduction pathways of the potent mycoparasite Trichoderma atroviride revealed the involvement of Tmk1, a mitogen-activated protein kinase, in triggering the mycoparasitic response. We previously showed that mutants missing Tmk1 exhibit reduced mycoparasitic activity against several plant pathogenic fungi. In this study we identified the most robustly regulated targets governed by Tmk1 during mycoparasitism by whole transcriptome gene expression profiling using a custom microarray.
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
Project description:To investigate the potential role in mycoparasitism, microarrays were used to examine T. reesei 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. 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).
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 investigate the potential role in mycoparasitism, microarrays were used to examine T. atroviride 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. Two biological poolw 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).
Project description:The Solexa/Illuminaâs digital gene expression (DGE) system was used to gain insight into the broad range of transcriptional responses during the vegetative growth, sclerotial development, myceliogenic germination, carpogenic germination, apothecium formation (stipe) and infection of Sclerotinia sclerotiorum. We obtained a sequencing depth of approximately 3.3 million clean tags per cDNA library. Tag mapping indicated that these six cDNA libraries in total represented more than 66.7% of all of the genes presented in the predicted transcript databases of the Broad Institute. Thouthands of differentially expressed genes were indentified during the various developmental stages compared to the vegetative growth stage. Our results could increase and deepen the understanding of the vegetative and reproductive development as well as the infection of S. sclerotiorum The S. sclerotiorum strain Ep-1PNA367 was grown or treated under different conditions, and samples were collected for RNA extraction for DGE analysis during the following stages: (i) Vegetative stage: activating hyphal agar discs of the Ep-1PNA367 stain were placed on a cellophane membrane overlaid onto PDA medium at 20°C; subsequently, the mycelia were collected at 12, 24, 36, 48 and 60 h; (ii) Sclerotial formation stage: the colonies growing on the cellophane membrane overlaid onto PDA medium were further incubated under the same conditions and then the cultures were collected at 84, 96, 108, 120 and 132 h; (iii) Early stages of infection: fresh hyphal fragments of the Ep-1PNA367 strain were overlaid onto sterilized cheese cloth, which was overlaid onto the leaves of the A. thaliana ecotype Columbia-0, followed by inoculation at 20°C with 100% relative humility; the cheese cloth with hyphae was then rolled up from the leaves at 9 h and 12 h; (iv) Sclerotial myceliogenic germination stage: sclerotia were surface sterilized with sodium hypochlorite and were sowed on a PDA plate at 20°C to induce myceliogenic germination, and when approximately 50% of sclerotia had germinated, the sclerotia were harvested; (v) Sclerotial carpogenic germination stage: sclerotia were dried at room temperature and were pretreated in a freezer (4-6°C) for up to one month and then were surface sterilized and sowed on wet sterilized sands in a plate at 15°C to induce carpogenic germination; when approximately 50% of the sclerotia germinated (stipes having only emerged from sclerotia), the sclerotia were harvested; and (vi) Early apothecial formation stage: sclerotia were allowed to grow in the same incubator, and the stipes were cut and collected immediately before apothecium formation for RNA extraction. Finally, different time-point samples from the vegetative stage, sclerotial formation stage and infection stage were pooled together respectively according to equal quantities for RNA extraction.
Project description:Aspergillus flavus contaminates crops during preharvest and post-harvest periods and produce carcinogenic mycotoxin aflatoxins posing severe threat to food safety and human health. To identify potential targets to tackle aflatoxin contamination, we have characterized a novel Afper1, sharing sequence identity with the yeast protein per1, regulating cell development and secondary metabolism in A. flavus. Notably, proteomics analysis revealed that the enzymes involved in extracellular hydrolases, conidial development, ER homeostasis, and aflatoxin biosynthesis significantly varied. Unexpectedly, enzymes participated in scavenging ROS including catA, catB, cpeB, and sodM were significantly downregulated and the accumulated ROS and sensitivity to hydrogen peroxide were confirmed by experiments. Surprisingly, Afper1 deletion significantly unregulated heterochromatin protein (HepA) and downregulated GNAT family acetyltransferase involved in heterochromatin formation. Accompanying the accumulated ROS and chromatin remodelling, enzymes participating in aflatoxins, ustiloxin B, and gliotoxin were impaired. These results implied that Afper1 affected chromatin remodelling and disturbed ER homeostasis leading to the accumulation of ROS, and ultimately resulted in growth defect and impaired secondary metabolites biosynthesis.
Project description:In this study, we obtain FoAPY1 transgenic tomato plants (2417-GFP) and control plants (GFP). All target tomato plants were identified by WB using anti-GFP antibody and all transgenic tomato plants has no differences in morphological and growth rate compared with wild type tomato plants. In order to detect the potential functional mechanism of FoAPY1 protein in the host plant, the proteomic analysis was performed to analyze differentially abundant proteins in two type tomato plants
Project description:A self-designed Trichoderma high density oligonuclotide (HDO) microarray (Roche-NimbleGen, Inc., Madison, WI, USA) was constructed in a similar way than a previous Trichoderma HDO microarray (Samolski et al., 2009). The microarray was composed of 392,779 60-mer probes designed against 13,443 EST-derived transcripts (Trichochip-1) and the genomes of T. atroviride (11,100 genes) and T. virens (11,643 genes). The Trichochip-1 ESTs were obtained from 28 cDNA libraries from eight different species (representing the biodiversity of this genus: T. harzianum, T. atroviride, T. asperellum, T. viride, T. longibrachiatum, T. virens, T. stromaticum and T. aggresivum), under a wide range of growth conditions, including biocontrol-related conditions and different nutritional situations (VizcaÃno et al., 2006). The Trichochip1 EST database was generated in the TrichoEST project funded by the EU (QLK3-CT-2002-02032). Confrontations were carried out between the T. harzianum T34 or nox1 overexpressed transformant Tnox5 and P. ultimum. Agar plugs cut from the growing edge of a 4-day colony of Trichoderma and Pythium were placed 2 cm from the border on the opposite side of the same petri plates containing PDA covered with sterile cellophane sheets. Dual cultures were allowed to grow at 25 ºC and mycelia were collected from the interaction zone in confrontations between P. ultimum and T. harzianum T34 or Tnox5 strains. Seven PDA plates were used for each condition considered and RNAs were extracted and the corresponding cDNAs were use to hybridize by triplicate the Trichoderma HDO microarray.
Project description:A self-designed Trichoderma high density oligonuclotide (HDO) microarray (Roche-NimbleGen, Inc., Madison, WI, USA) was constructed in a similar way than a previous Trichoderma HDO microarray (Samolski et al., 2009). The microarray was composed of 392,779 60-mer probes designed against 13,443 EST-derived transcripts (Trichochip-1) and the genomes of T. atroviride (11,100 genes) and T. virens (11,643 genes). The Trichochip-1 ESTs were obtained from 28 cDNA libraries from eight different species (representing the biodiversity of this genus: T. harzianum, T. atroviride, T. asperellum, T. viride, T. longibrachiatum, T. virens, T. stromaticum and T. aggresivum) under a wide range of growth conditions, including biocontrol-related conditions and different nutritional situations (VizcaÃno et al., 2006). The Trichochip1 EST database was generated in the TrichoEST project funded by the EU (QLK3-CT-2002-02032) T. atroviride P1 mycelium grown (approximately for 24h) at 25ºC on a cellophane sheet on PDA (Difco) plates before contact (at a distance of 5 mm) a R. solani colony grown under identical conditions in the same plate was compared with T. atroviride P1 mycelium after contact (5 mm) the above R. solani colony (mycoparasitic interaction). RNAs from both conditions were extracted and the corresponding cDNAs were use to hybridize by triplicate the Trichoderma HDO microarray.
Project description:We have recently shown that the coprophilous model mushroom Coprinopsis cinerea transcribes a broad array of genes encoding defense proteins in the vegetative mycelium and fruiting bodies that target bacterial competitors and animal predators challenging the respective tissues of this fungus. In addition, we have demonstrated in previous work that two nematotoxic defense proteins from Coprinopsis, CGL1 and CGL2, were induced in vegetative mycelium challenged with the predatory nematode Aphelenchus avenae; however, the specificity and broadness of this response remained unclear. In order to resolve these issues, we sequenced the poly(A)-positive transcriptome of vegetative mycelium of C. cinerea confronted with nematode predation, hyphal mechanical damage or bacterial co-culture.