Project description:A collection of 237,000 expressed sequence tags generated by the Sugarcane EST sequencing project (SUCEST) was analyzed in search of signal transduction components. The SUCAST (Sugarcane Signal Transduction) Catalogue contains over 3500 components, with around 2900 involved in several aspects of cell signaling and transcription. Sequence comparisons and conserved protein domain analysis revealed 477 receptors, 510 protein kinases, 107 protein phosphatases, a large number of small GTPases, G-proteins, members of the calcium and inositol metabolism, and other signal transduction-related proteins. Over 600 transcription factors were also indexed. Moreover, 437 genes with no matches in the public databases and 111 genes of unknown function were catalogued. Several of the SUCEST cDNA libraries were derived from plants submitted to abiotic stresses or infected with endophytic nitrogen fixing bacteria and stress and pathogen response-related genes were also annotated. The abundance of transcripts among six different sugarcane tissues (flowers, roots, leaves, lateral buds, 1st and 4th internodes) was evaluated using microarrays and expression profile clustering. We identified 216 genes that are significantly more abundant in one of the tissues analyzed. A subset of the data was validated by real-time PCR. Additionally, genes with similar expression levels among different tissues were identified. The characterization of these elements and their promoters can aid in the development of tools for the genetic manipulation of this plant species and other economically important grasses. Keywords: other
Project description:Mitigation of N2O-emissions from soils is needed to reduce climate forcing by food production. Inoculating soils with N2O-reducing bacteria would be effective, but costly and impractical as a standalone operation. Here we demonstrate that digestates obtained after biogas production may provide a low-cost and widely applicable solution. Firstly, we show that indigenous N2O-reducing bacteria in digestates grow to high levels during anaerobic enrichment under N2O. Gas kinetics and meta-omic analysis show that the N2O respiring organisms, recovered as metagenome-assembled genomes (MAGs) grow by harvesting fermentation intermediates of the methanogenic consortium. Three digestate-derived denitrifying bacteria were obtained through isolation, one of which matched the recovered MAG of a dominant Dechloromonas-affiliated N2O reducer. While the identified N2O-reducers encoded genes required for a full denitrification pathway and could thus both produce and sequester N2O, their regulatory traits predicted that they act as N2O-sinks in the current system. Secondly, moving towards practical application, we show that these isolates grow by aerobic respiration in digestates, and that fertilization with these enriched digestates reduces N2O emissions. This shows that the ongoing implementation of biogas production in agriculture opens a new avenue for cheap and effective reduction of N2O emissions from food production.
Project description:Gene regulation is one of the most ubiquitous processes in biology. And yet, while the catalogue of 15 bacterial genomes continues to expand rapidly, we remain ignorant about how almost all of the genes in 16 these genomes are regulated. Characterizing the molecular mechanisms by which regulatory sequences 17 operate still requires focused efforts using low-throughput methods. Here we show how a combination of 18 massively parallel reporter assays, mass spectrometry, and information-theoretic modeling can be used 19 to dissect bacterial promoters in a systematic and scalable way. We demonstrate this method on both 20 well-studied and previously uncharacterized promoters in the enteric bacterium Escherichia coli. In all 21 cases we recover nucleotide-resolution models of promoter mechanism. For some promoters, including 22 previously unannotated ones, we can further extract quantitative biophysical models describing 23 input-output relationships. This method opens up the possibility of exhaustively dissecting the 24 mechanisms of promoter function in E. coli and a wide range of other bacteria.