Project description:During the last decades, the use of plant growth promoting bacteria (PGPB) has been found to increase crop yield and quality and to confer abiotic and biotic stress tolerance. However, until now the PGPB mechanism to enhance plant performances is not clearly defined. Recently, our findings demonstrated that inoculations with both Kocuria rhizophila and Streptomyces violaceoruber, as well as their combination, determined an increase of tomato (Solanum lycopersicum) growth and development. In this study, through an advanced differential proteomic approach on tomato leaves, plant molecular mechanisms affected by both K. rhizophila and S. violaceoruber have been elucidated. To this aim, tomato plants were treated with K. rhizophila and/or Streptomyces violaceoruber cultures and grown on coconut fiber in greenhouse. In particular, PGPB treatments were conducted twice, on seed and after two weeks from the seedling by fertirrigation. Thus, the analyses have been performed at 14 days after sowing (DAS) (T1) and 42 DAS (T2). The results confirmed the growth stimulation ability of K. rhizophila/Streptomyces violaceoruber, showing shoot fresh and dry weight significantly improved at each time sampling. For the early phase (DAS-T1) comparative proteomics analysis of tomato plant leaves, 2 biological replicates were set up for the plants used as control (i.e. not subjected to treatment - samples I1 and I2-control I), 2 biological replicates for plants subjected to treatment with K. rhizophila (samples L1 and L2-treatment L), 2 biological replicates for plants subjected to treatment with S. violaceoruber (samples M1 and M2-treatment M), and 2 biological replicates for plants subjected to treatment with a mix of the two bacterial strains (samples N1 and N2-treatment N), for a total of 8 samples of leaf protein extracts. For the late phase (DAS-T2) comparative proteomics analysis of tomato plant leaves, 2 biological replicates were set up for the plants used as control (i.e. not treated - samples A1 and A2 - control A), 2 biological replicates for plants subjected to treatment with K. rhizophila (samples B1 and B2-treatment B), 2 biological replicates for plants subjected to treatment with S. violaceoruber (samples C1 and C2-treatment C), and 2 biological replicates for plants subjected to treatment with a mix of the two bacterial strains (samples D1 and D2-treatment D), for a total of 8 samples of leaf protein extracts. Proteomic analysis was able to identify 239 and 203 significantly differentially represented proteins (DRPs) at T1 and T2, respectively, comparing PGPB-treated vs. untreated control plants. KEGG Orthology (KO) identified DRP belonging to photosynthesis, biosynthesis of secondary metabolites, and carbon metabolism.
Project description:We identified genome-wide binding regions of NdgR in Streptomyces coelicolor using chromatin immunoprecipitation sequencing (ChIP-seq). We constructed 6×myc-tagged NdgR strain using homologous recombination with myc-tagging vector. Analysis of the sequencing data aligned to Streptomyces coelicolor genome database (NC_003888).
Project description:This study compared the genome of Streptomyces rimosus rimosus against that of Streptomyces coelicolor. It also compared 4 strains with changes in oxytetracycline production and derived from G7, the type strain, against G7. Keywords: Comparative genomic hybridization
Project description:We performed ribosome profiling which is the deep-sequencing of mRNA fragments protected by translating ribosome for two Streptomyces species through different growth phases to provide the translatome data
Project description:Two component sensor-response regulator systems (TCSs) are very common in the genomes of the Streptomyces species that have been fully sequenced to date. It has been suggested that this large number is an evolutionary response to the variable environment that Streptomyces encounter in soil. Notwithstanding this, TCSs are also more common in the sequenced genomes of other Actinomycetales when these are compared to the genomes of most other eubacteria. In this study, we have used DNA/DNA genome microarray analysis to compare fourteen Streptomyces species and one closely related genus to Streptomyces coelicolor in order to identify a core group of such systems. This core group is compared to the syntenous and non-syntenous TCSs present in the genome sequences of other Actinomycetales in order to separate the systems into those present in Actinomycetales in general, the Streptomyces specific systems and the species specific systems. Horizontal transfer does not seem to play a very important role in the evolution of the TCS complement analyzed in this study. However, cognate pairs do not necessarily seem to evolve at the same pace, which may indicate the evolutionary responses to environmental variation may be reflected differently in sequence changes within the two components of the TCSs. The overall analysis allowed subclassification of the orphan TCSs and the TCS cognate pairs and identification of possible targets for further study using gene knockouts, gene overexpression, reporter genes and yeast two hybrid analysis.
Project description:When Streptomyces violaceoruber grows together with Streptomyces sp. MG7-G1, it reacts with strongly induced droplet production on its aerial mycelium. Initially the metabolite profile of droplets from S. violaceoruber in co-culture with Streptomyces sp. MG7-G1 was compared to samples from S. violaceoruber in single-culture by using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Then, the exudate from agar plates of co-cultures and single cultures (after freezing and thawing) was also analysed. Several compounds were only observed when S. violaceoruber was grown in co-culture. Based on their high-resolution ESI mass spectra and their comparable retention times to the calcium-dependent antibiotics (CDAs) produced by S. violaceoruber, the new compounds were suspected to be deacylated calcium-dependent antibiotics (daCDAs), lacking the 2,3-epoxyhexanoyl residue of CDAs. This was verified by detailed analysis of the MS/MS spectra of the daCDAs in comparison to the CDAs. The major CDA compounds present in calcium ion-supplemented agar medium of co-cultures were daCDAs, thus suggesting that Streptomyces sp. MG7-G1 expresses a deacylase that degrades CDAs.