title: Transcriptomic and Proteomic Profiling of Anabaena sp. Strain 90 under Inorganic Phosphorus Stress.
abstract: Inorganic phosphorus (Pi) is one of the main growth-limiting factors of diazotrophic cyanobacteria. Due to human activity, the availability of Pi has increased in water bodies, resulting in eutrophication and the formation of massive cyanobacterial blooms. In this study, we examined the molecular responses of the cyanobacterium Anabaena sp. strain 90 to phosphorus deprivation, aiming at the identification of candidate genes to monitor the Pi status in cyanobacteria. Furthermore, this study increased the basic understanding of how phosphorus affects diazotrophic and bloom-forming cyanobacteria as a major growth-limiting factor. Based on RNA sequencing data, we identified 246 differentially expressed genes after phosphorus starvation and 823 differentially expressed genes after prolonged Pi limitation, most of them related to central metabolism and cellular growth. The transcripts of the genes related to phosphorus transport and assimilation (pho regulon) were most upregulated during phosphorus depletion. One of the most increased transcripts encodes a giant protein of 1,869 amino acid residues, which contains, among others, a phytase-like domain. Our findings predict its crucial role in phosphorus starvation, but future studies are still needed. Using two-dimensional difference in gel electrophoresis (2D-DIGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), we found 43 proteins that were differentially expressed after prolonged phosphorus stress. However, correlation analysis unraveled an association only to some extent between the transcriptomic and proteomic abundances. Based on the present results, we suggest that the method used for monitoring the Pi status in cyanobacterial bloom should contain wider combinations of pho regulon genes (e.g., PstABCS transport systems) in addition to the commonly used alkaline phosphatase gene alone.
authors.affiliation: Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Jonna
authors.initials: J
authors.lastname: Teikari
authors.affiliation: Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Julia
authors.initials: J
authors.lastname: Österholm
authors.affiliation: Genetics & Experimental Bioinformatics, Institute of Biology III, University of Freiburg, Freiburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kopf
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Battchikova
authors.affiliation: Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Wahlsten
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors.forename: Eva-Mari
authors.initials: EM
authors.lastname: Aro
authors.affiliation: Genetics & Experimental Bioinformatics, Institute of Biology III, University of Freiburg, Freiburg, Germany.
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Hess
authors.affiliation: Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland Kaarina.Sivonen@Helsinki.Fi.
authors.forename: Kaarina
authors.initials: K
authors.lastname: Sivonen
mesh_terms: D017033:Anabaena / Q000187:drug effects* / Q000254:growth & development; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D053858:Metabolic Networks and Pathways / Q000235:genetics; D010758:Phosphorus / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological; D053719:Tandem Mass Spectrometry
chemical_list: D020543:Proteome; D012329:RNA, Bacterial; D010758:Phosphorus