Project description:Metagenome data from soil samples were collected at 0 to 10cm deep from 2 avocado orchards in Channybearup, Western Australia, in 2024. Amplicon sequence variant (ASV) tables were constructed based on the DADA2 pipeline with default parameters.
Project description:mzML files from the analysis of SPE-concentrated surface water samples collected in different rivers in Luxembourg between 2019 and 2022 through the collaborative work between the Environmental Cheminformatics Group (LCSB, University of Luxembourg) and the Luxembourg Administration de la gestion de l eau (AGE). The according sampling locations related to each file can be found in the supplementary xlsx file.
Project description:Biofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of polysaccharides, proteins, and extracelluar (e)DNA, with eDNA being required for the formation and integrity of biofilms. Here we demonstrate that the spatial and temporal release of eDNA is regulated by BfmR, a regulator essential for Pseudomonas aeruginosa biofilm development. The expression of bfmR coincided with localized cell death and DNA release, with high eDNA concentrations localized to the outer part of microcolonies in the form of a ring and as a cap on small clusters. Additionally, eDNA release and cell lysis increased significantly following bfmR inactivation. Genome-wide transcriptional profiling indicated that bfmR was required for repression of genes associated with bacteriophage assembly and bacteriophage-mediated lysis. In order to determine which of these genes were directly regulated by BfmR, we utilized chromatin immunoprecipitation (ChIP) analysis to identify the promoter of PA0691, termed here phdA, encoding a previously undescribed homologue of the prevent-host-death (Phd) family of proteins. Lack of phdA expression coincided with impaired biofilm development, increased cell death and bacteriophage release, a phenotype comparable to ΔbfmR. Expression of phdA in ΔbfmR biofilms restored eDNA release, cell lysis, release of bacteriophages, and biofilm formation to wild type levels. Moreover, overexpression of phdA rendered P. aeruginosa resistant to lysis mediated by superinfective bacteriophage Pf4 which was only detected in biofilms. The expression of bfmR was stimulated by conditions resulting in membrane perturbation and cell lysis. Thus, we propose that BfmR regulates biofilm development by controlling bacteriophage-mediated lysis and thus, cell death and eDNA release, via PhdA.
Project description:Virus resistances that are recessively inherited are associated with loss-of-susceptibility resistance alleles. Resistance to Watermelon mosaic virus (WMV) of melon accession TGR-1551 is expressed as a drastic reduction of the virus titer, and is recessively inherited. In this work, viral RNA accumulation was measured in TGR-1551 and in susceptible WMV-infected melon plants by real time quantitative PCR (qPCR), and gene expression of 17,443 unigenes represented in a melon microarray was monitored in a time-course experiment. Virus accumulation was higher in inoculated cotyledons of the resistant genotype up to 7 days post-inoculation; from this time on, virus accumulation was much higher in plants of the susceptible genotype. Microarray experiments were carried with samples from inoculated cotyledons at 1 and 3 dpi to monitor early changes in response to virus infection, and at 7 dpi. Samples from systemically infected leaves harvested at 15 dpi were also included in the analysis. Results showed much more profound transcriptomic alterations in resistant plants compared to susceptible ones. Analyses of gene expression profiles reveal deep and extensive transcriptomic alterations in TGR-1551 plants, many of them involving pathogen response-related genes. Overall, data suggested that resistance to WMV in TGR-1551 is associated with a defense response, contrasting with its recessive nature.