Project description:Acremonium chrysogenum is the industrial producer of cephalosporin C. We isolated a mutant (AC554) from a T-DNA inserted library of A. chrysogenum. AC554 exhibited reduced conidiation and lack of cephalosporin C production. In consistent, the transcription of cephalosporin biosynthetic genes pcbC and cefEF was obviously decreased in AC554. TAIL-PCR and sequence analysis indicated that a T-DNA was inserted in the upstream of an open reading frame (ORF) which was designated AcmybA. Sequence analysis indicated that AcmybA encodes a novel Myb domain containing transcriptional factor. Observation of red fluorescence protein (RFP) tagged AcMybA showed that AcMybA is naturally located in the nuclear of A. chrysogenum. Transcription analysis demonstrated that AcmybA was overexpressed in AC554. In contrast with AC554, the AcmybA deleted mutant (DAcmybA) overproduced conidia in LPE medium and increased cephalosporin production during fermentation. To determine the genes under the influence of AcmybA, we sequenced and compared the transcriptome of DAcmybA, AC554 and the wild-type strain at different developmental stages. Results confirmed the repression of AcMybA on the key conidiation regulatory gene AcbrlA and the cephalosporin biosynthetic genes. Among the targets of AcMybA, 10 putative regulatory genes were selected and overexpressed in A. chrysogenum. Taken together, our results indicate that AcMybA negatively regulates conidiation and cephalosporin production in A. chrysogenum.
Project description:B. napus, a widely cultivated oilseed crop spanning roughly 35 million hectares world-wide (Faostat , 2022), faces various stress factors including salt stress which reduces plant height, size, and yield (Shahza d et al., 2022; Naheed et al., 2021). Endophytic microorganisms are known to promote plant growth and biomass production (Rho et al., 2018, Azad et al., 2016, Zhang et al., 2019). In this study, inoculation with endophyte Acremonium alternatum increased both fresh and dry weight under salt stress conditions. Further molecular analyses provided insights into potential mechanisms involved, highlighting a putative role of abscisic acid in mediating ROS metabolism and ion sequestering. These findings contribute to our understanding of plant-fungi interactions and offer promising leads for developing novel biological agents to improve crop production under the challenges posed by climate change.
Project description:The eubacterial species Streptomyces coelicolor proceeds through a complex growth cycle in which morphological differentiation/development is associated with a transition from primary to secondary metabolism and the production of antibiotics. We used DNA microarrays and mutational analysis to investigate the expression of individual genes and multigene antibiotic biosynthetic pathways during these events. We identified expression patterns in biosynthetic, regulatory, and ribosomal protein genes that were associated highly specifically with particular stages of development. A knowledge-based algorithm that correlates temporal changes in expression with chromosomal position identified groups of contiguous genes expressed at discrete stages of morphological development, inferred the boundaries of known antibiotic synthesis gene loci, and revealed novel physical clusters of coordinately regulated genes. Microarray analysis of RNA from cells mutated in genes regulating synthesis of the antibiotics actinorhodin (Act) and undecylprodigiosin (Red) identified proximate and distant sites that contain putative ABC transporter and two-component system genes expressed coordinately with genes of specific biosynthetic pathways and indicated the existence of two functionally and physically discrete regulons in the Red pathway.
Project description:The eubacterial species Streptomyces coelicolor proceeds through a complex growth cycle in which morphological differentiation/development is associated with a transition from primary to secondary metabolism and the production of antibiotics. We used DNA microarrays and mutational analysis to investigate the expression of individual genes and multigene antibiotic biosynthetic pathways during these events. We identified expression patterns in biosynthetic, regulatory, and ribosomal protein genes that were associated highly specifically with particular stages of development. A knowledge-based algorithm that correlates temporal changes in expression with chromosomal position identified groups of contiguous genes expressed at discrete stages of morphological development, inferred the boundaries of known antibiotic synthesis gene loci, and revealed novel physical clusters of coordinately regulated genes. Microarray analysis of RNA from cells mutated in genes regulating synthesis of the antibiotics actinorhodin (Act) and undecylprodigiosin (Red) identified proximate and distant sites that contain putative ABC transporter and two-component system genes expressed coordinately with genes of specific biosynthetic pathways and indicated the existence of two functionally and physically discrete regulons in the Red pathway. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
