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Summary Bryophytes harbour microbiomes, including diverse communities of fungi. The molecular mechanisms by which perennial mosses interact with these fungal partners along their senescence gradients are unknown, yet this is an ideal system to study variation in gene expression associated with trophic state transitions. We investigated differentially expressed genes of fungal communities and their hostDicranum scopariumacross its naturally occurring senescence gradient using a metatranscriptomic approach. Higher activity of fungal nutrient‐related (carbon, nitrogen, phosphorus and sulfur) transporters and Carbohydrate‐Active enZyme (CAZy) genes was detected toward the bottom, partially decomposed, layer of the moss. The most prominent variation in the expression levels of fungal nutrient transporters was from inorganic nitrogen‐related transporters, whereas the breakdown of organonitrogens was detected as the most enriched gene ontology term for the hostD. scoparium, for those transcripts having higher expression in the partially decomposed layer. The abundance of bacterial rRNA transcripts suggested that more living members ofCyanobacteriaare associated with the photosynthetic layer ofD. scoparium, while members ofRhizobialesare detected throughout the gametophytes. Plant genes for specific fungal–plant communication, including defense responses, were differentially expressed, suggesting that different genetic pathways are involved in plant‐microbe crosstalk in photosynthetic tissues compared to partially decomposed tissues.
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Gene Expression of Haloferax volcanii on Intermediate and Abundant Sources of Fixed Nitrogen
Haloferax volcanii, a well-developed model archaeon for genomic, transcriptomic, and proteomic analyses, can grow on a defined medium of abundant and intermediate levels of fixed nitrogen. Here we report a global profiling of gene expression of H. volcanii grown on ammonium as an abundant source of fixed nitrogen compared to l-alanine, the latter of which exemplifies an intermediate source of nitrogen that can be obtained from dead cells in natural habitats. By comparing the two growth conditions, 30 genes were found to be differentially expressed, including 16 genes associated with amino acid metabolism and transport. The gene expression profiles contributed to mapping ammonium and l-alanine usage with respect to transporters and metabolic pathways. In addition, conserved DNA motifs were identified in the putative promoter regions and transcription factors were found to be in synteny with the differentially expressed genes, leading us to propose regulons of transcriptionally co-regulated operons. This study provides insight to how H. volcanii responds to and utilizes intermediate vs. abundant sources of fixed nitrogen for growth, with implications for conserved functions in related halophilic archaea.
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- Award ID(s):
- 1642283
- PAR ID:
- 10202995
- Date Published:
- Journal Name:
- International Journal of Molecular Sciences
- Volume:
- 20
- Issue:
- 19
- ISSN:
- 1422-0067
- Page Range / eLocation ID:
- 4784
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/ijms20194784
