Project description:The ecological significance of light perception in non-phototrophic bacteria remains largely elusive. In terrestrial environments, diurnal oscillations in light are often temporally coupled to other environmental changes, including increased temperature and evaporation. Here we report that light functions as an anticipatory cue that triggers protective adaptations to tolerate a future rapid loss of environmental water in leaf-associated Pseudomonas syringae pv. syringae (Pss) and other terrestrial pseudomonads. Global transcriptome analyses in Pss showed that light control occurs almost entirely through a bacteriophytochrome photoreceptor that senses red, far-red and blue wavelengths and influences 30% of the Pss genome. Bacteriophytochrome-mediated light control disproportionally upregulates water-stress adaptation functions and confers enhanced fitness when cells encounter light prior to water limitation. These data demonstrate that non-phototrophic bacteria can use light as a cue to mount an adaptive anticipatory response against a physiologically unrelated but ecologically coupled stress.
Project description:Chemical modifications to the tails of histone proteins act as gene regulators that play a pivotal role in adaptive responses to environmental stress. Determining the short and long term kinetics of histone marks is essential for understanding their functions in adaptation. We used Caenorhabditis elegans as a model organism to study the histone modification kinetics in response to environmental stress, taking advantage of their ability to live in both terrestrial and aquatic environments. We investigated the multigenerational genome-wide dynamics of five histone marks (H3K4me3, H3K27me3, H4K20me1, H3K36me1, and H3K9me3) by maintaining P0 animals on terrestrial (agar plates), F1 in aquatic cultures, and F2 back on terrestrial environments. We determined the distributions of histone marks in the gene promoter regions and found that H4K20me1, H3K36me1, and H3K9me3 showed up to eleven-fold differences in density, whereas H3K4me3 and H3K27me3 remained highly constant during adaptation from terrestrial to aquatic environments. Furthermore, we predicted that up to five combinations of histone marks can co-occupy single gene promoters and confirmed the colocalization of these histone marks by structured illumination microscopy. The co-occupancy increases with environment changes and different co-occupancy patterns contribute to variances in gene expressions and thereby presents a supporting evidence for the histone code hypothesis.
Project description:The diversity and environmental distribution of the nosZ gene, which encodes the enzyme responsible for the consumption of nitrous oxide, was investigated in marine and terrestrial environments using a functional gene microarray. The microbial communities represented by the nosZ gene probes showed strong biogeographical separation, with communities from surface ocean waters and agricultural soils significantly different from each other and from those in oceanic oxygen minimum zones. Atypical nosZ genes, usually associated with incomplete denitrification pathways, were detected in all the environments, including surface ocean waters. The abundance of nosZ genes, as estimated by quantitative PCR, was highest in the agricultural soils and lowest in surface ocean waters.
2018-10-19 | GSE121473 | GEO
Project description:Phylotranscriptomics of Australian terrestrial orchids
Project description:16s RNA gene sequencing data from seawater, bed sediment and steel corrosion samples from Shoreham Harbour, UK, collected to allow bacterial species comparisons between microbially influenced corrosion, the surrounding seawater, and the sea bed sediment at the seafloor and 50cm depth below seafloor.
Project description:Marine is one of the most important resources of microorganisms, including bacteria, actinomycetes, and fungi. As marine and terrestrial environments differ a lot in many aspects it is not surprising that the species and characteristics of microorganisms living there are very different. Interestingly, many marine microorganisms can find their congeners of the same species from terrestrial resources. The aim of this work is to evaluate the intraspecies differences between marine and terrestrial actinomycetes on metabolic level and to uncover the mechanism responsible for the differences. To address this, we carried out comparative metabolomics study on Nesterenkonia flava strains isolated from marine and terrestrial environments. The results showed that marine strains were clearly distinguished from their terrestrial congeners on the principal components analysis (PCA) scores plot of intracellular metabolites. The markers responsible for the discrimination of marine and terrestrial strains were figured out using loading plot from partial least squares discrimination analysis (PLS-DA). Pathway analysis based on PLS-DA, univariate analysis, and correlation analysis of metabolites showed that the major differential metabolites between the terrestrial N. flava and the marine ones were involved in osmotic regulation, redox balancing, and energy metabolism. Together, these insights provide clues as to how the previous living environment of microbes affect their current metabolic performances under laboratory cultivation conditions.