Project description:We investigated the metabolism of six secondary metabolite producing fungi of the Penicillium genus, during nutrient depletion in the stationary phase of batch fermentations and assessed conserved metabolic responses across species using genome-wide transcriptional profiling. Coexpression analysis revealed that expression of secondary metabolite biosynthetic genes correlates with expression of genes associated with pathways responsible for generation of precursor metabolites for secondary metabolism. Our results highlight the main metabolic routes for precursor supply of the secondary metabolism during nutrient depletion, and suggests that regulation of fungal metabolism is tailored to meet the demands for secondary metabolite production. These findings can aid in identifying wild type species, which are optimized for production of specific secondary metabolites, and therefore can be utilized as high yielding cell factories.
Project description:Blackcurrant fruit collected at six stages of development were assessed for changes in gene expression using custom whole transcriptome microarrays and for variation in metabolite content using a combination of liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Principal components analysis demonstrated that fruit development could be clearly defined according to their transcript or metabolite profiles. During early developmental stages, metabolite profiles were dominated by amino acids and tannins, whilst transcript profiles were enriched in functions associated with cell division, anatomical structure morphogenesis and cell wall metabolism. During mid fruit development, fatty acids accumulated and transcript profiles were consistent with seed and embryo development. At the later stages, sugars and anthocyanins accumulated consistent with transcript profiles that were associated with secondary metabolism. Transcript data also indicated active signalling during later stages of fruit development. A targeted analysis of signalling networks revealed a dynamic activation and repression of almost 60 different transcripts encoding transcription factors across the course of fruit development, many of which have been demonstrated as pivotal to controlling such processes in other species. Transcripts associated with cytokinin and gibberellin were highly abundant at early fruit development, whilst those associated with ABA and ethylene tended to be more abundant at later stages. The data presented here provides an insight into fruit development in blackcurrant and provides a foundation for further work in the elucidation of the genetic basis of fruit quality.
Project description:Antibiotic biosynthesis in Streptomyces species is controlled by a complex genetic and biochemical network of global and pathway specific regulators. Details of their precise interactions in mediating temporal and spatial expression of secondary metabolite genes remain poorly defined. In this study, we employed whole-genome microarrays to investigate the temporal transcriptome profiles of S. coelicolor A3(2) wild type and regulatory mutants.
Project description:Antibiotic biosynthesis in Streptomyces species is controlled by a complex genetic and biochemical network of global and pathway specific regulators. Details of their precise interactions in mediating temporal and spatial expression of secondary metabolite genes remain poorly defined. In this study, we employed whole-genome microarrays to investigate the temporal transcriptome profiles of S. coelicolor A3(2) wild type and regulatory mutants.
Project description:Antibiotic biosynthesis in Streptomyces species is controlled by a complex genetic and biochemical network of global and pathway specific regulators. Details of their precise interactions in mediating temporal and spatial expression of secondary metabolite genes remain poorly defined. In this study, we employed whole-genome microarrays to investigate the temporal transcriptome profiles of S. coelicolor A3(2) wild type and regulatory mutants.
Project description:Diverse expression patterns for secondary metabolism gene clusters from Aspergillus flavus under different environmental conditions and in genetic mutants: Insights into regulation of cyclopiazonic acid along with aflatoxin Species of Aspergillus produce a diverse array of secondary metabolites, and recent genomic analysis predicts that these species have the capacity to synthesize many more compounds. It has been possible to infer the presence of 55 gene clusters associated with secondary metabolism in A. flavus. Presumably, secondary metabolites play important roles in the ecology of the producing species, but functions for most secondary metabolites remain unknown. Only three metabolic pathways have been associated with the predicted clusters in A. flavus. These include aflatoxin, cyclopiazonic acid (CPA), and aflatrem. To gain insight into the regulation of, and infer ecological significance for the 55 secondary metabolite gene clusters predicted in A. flavus, we examined their expression over 28 diverse conditions. Variables included culture media and temperature, fungal development, colonization of developing maize seeds, and misexpression of laeA, the global regulator of secondary metabolism. Hierarchical clustering analysis of expression profiles allowed us to categorize the gene clusters into four distinct clades. Gene clusters for the production of aflatoxins, CPA, and seven other unknown compound(s) were identified as belonging to one clade. To further explore the relationships found by gene expression analysis, aflatoxin and CPA production were quantified under five different cell culture environments known to be conducive or non-conducive for aflatoxin biosynthesis and during colonization of developing maize seeds. Results from these studies showed that secondary metabolism gene clusters have distinctive gene expression profiles. Aflatoxin and CPA were found to have unique regulation but similar enough that they would be expected to co-occur in commodities colonized with A. flavus.
2010-03-11 | GSE15435 | GEO
Project description:Secondary Metabolite Production from Pseudomonas
Project description:Antibiotic biosynthesis in Streptomyces species is controlled by a complex genetic and biochemical network of global and pathway specific regulators. Details of their precise interactions in mediating temporal and spatial expression of secondary metabolite genes remain poorly defined. In this study, we employed whole-genome microarrays to investigate the temporal transcriptome profiles of S. coelicolor A3(2) deltaSCO6268::kan mutant strain (WL6268) and compare it to the wild-type M145 strain. SCO6268 is a putative histidine kinase.