Project description:Chaetomium globosum is a model of conditional pathogens abundant on a wide variety of substrates in soil, water, and atmosphere environments. Homothallic C. globosum produces hairy perithecia bearing meiotic ascospores that are resistant to harsh conditions for dispersal, and asexual reproduction of conidia has never been observed. RNAs were samples from nine distinct morphological stages during the nearly synchronic perithecial development for C. globosum. Unlike the heterothallic Neurospora crassa, the mating type gene mat a-1 showed comparatively lower expression changes but highly coordinate with expression regulation of mat A-1 in C. globosum. Key regulators, including orthologs of N. crassa sub-1, sub-1 dependent gene NCU00309, and asl-1, in the initiation of sexual development in response to light stimuli, showed similar regulation dynamics between C. globosum and N. crassa. Knockout phenotyping directed by the comparative analysis of transcriptomics between C. globosum and its’ closely related Neurospora crassa also suggested some genes that are critical for perithecial development. Among 24 secondary metabolism clusters composed more than 3 genes in C. globosum, 11 showed highly coordinated expression across the perithecial development, and dramatically up-regulation was recorded for all 12 genes in the cochliodones biosynthesis cluster. Up-regulation of chaetoglocin and aureonitol biosynthesis clusters was found to be associated with disturbance in early sexual development and with ascospore maturation. Similar to pathogenic Fusarium graminearum, C. globosum showed coordinately up-regulated expression of homologs of histidine kinases in hyperosmotic response pathways, consist with their ecology adapting to high humidity.
Project description:The thermophilic filamentous fungi Myceliophthora thermophila (Sporotrichum thermophile) and Thielavia terrestris are proficient decomposers of cellulose, suggesting that they will be a rich source of thermostable industrial enzymes for lignocellulose degradation. To identify the genes and proteins involved in this process, we explored the transcriptomes of M. thermophila and T. terrestris growing at 45 ºC on either glucose, alfalfa, or barley straw by short-read sequencing of extracted mRNA. To better understand the adaptations that allow these fungi to grow at elevated temperatures, we compared their transcriptomes when growing at 34C to their transcritomes at 45C, and also to the transcriptome of the related fungus Chaetomium globosum, which does not grow at 45C.
Project description:The thermophilic filamentous fungi Myceliophthora thermophila (Sporotrichum thermophile) and Thielavia terrestris are proficient decomposers of cellulose, suggesting that they will be a rich source of thermostable industrial enzymes for lignocellulose degradation. To identify the genes and proteins involved in this process, we explored the transcriptomes of M. thermophila and T. terrestris growing at 45 ºC on either glucose, alfalfa, or barley straw by short-read sequencing of extracted mRNA. To better understand the adaptations that allow these fungi to grow at elevated temperatures, we compared their transcriptomes when growing at 34C to their transcritomes at 45C, and also to the transcriptome of the related fungus Chaetomium globosum, which does not grow at 45C. RNA was extracted from cultures in early growth stage growing with glucose, alfalfa, or barley straw as carbon source at 34C or 45C (M. thermophila and T. terrestris); duplicate cultures were sampled in some conditions.
Project description:Most photosynthetically fixed carbon is contained in cell wall polymers present in plant biomasses, the largest organic carbon source in the biosphere. The degradation of these polymers for biotechnological purposes requires the combined action of several enzymes. To identify new activities, we examined which enzymes are activated by an endophytic strain of Chaetomium globosum to degrade cellulose-containing substrates. After biochemical analyses of the secretome of the fungus grown on cellulose or woody substrates, we took advantage of the available genomic data to identify potentially involved genes. After in silico identification of putative genes encoding either proteins able to bind to cellulose or glycohydrolases (GHs) of family 7, we investigated their transcript levels by reverse transcription-quantitative PCR (RT-qPCR). Our data suggest that eight genes compose the core of the cellulose-degrading system of C. globosum. Notably, the related enzymes belong structurally to the well-described GH families 5, 6, 7, 16, and 45, which are known to be the core of the cellulose degradation systems of several ascomycetes. The high expression levels of cellobiose dehydrogenase and two GH 61 enzymes suggest the involvement of this oxidoreductive synergic system in C. globosum. Transcript analysis along with relevant coding sequence (CDS) isolation and expression of recombinant proteins proved to be a key strategy for the determination of the features of two endoglucanases used by C. globosum for the first attack of crystalline cellulose. Finally, the possible involvement of transcriptional regulators described for other ascomycetes is discussed.
