title: The Complex Transcriptional Response ofAcaryochloris marinato Different Oxygen Levels.
abstract: Ancient oxygenic photosynthetic prokaryotes produced oxygen as a waste product, but existed for a long time under an oxygen-free (anoxic) atmosphere, before an oxic atmosphere emerged. The change in oxygen levels in the atmosphere influenced the chemistry and structure of many enzymes that contained prosthetic groups that were inactivated by oxygen. In the genome ofAcaryochloris marina, multiple gene copies exist for proteins that are normally encoded by a single gene copy in other cyanobacteria. Using high throughput RNA sequencing to profile transcriptome responses from cells grown under microoxic and hyperoxic conditions, we detected 8446 transcripts out of the 8462 annotated genes in the Cyanobase database. Two-thirds of the 50 most abundant transcripts are key proteins in photosynthesis. Microoxic conditions negatively affected the levels of expression of genes encoding photosynthetic complexes, with the exception of some subunits. In addition to the known regulation of the multiple copies ofpsbA, we detected a similar transcriptional pattern forpsbJandpsbU, which might play a key role in the altered components of photosystem II. Furthermore, regulation of genes encoding proteins important for reactive oxygen species-scavenging is discussed at genome level, including, for the first time, specific small RNAs having possible regulatory roles under varying oxygen levels.
authors.affiliation: Australian Research Council Centre of Excellence for Translational Photosynthesis and School of Biological Sciences, University of Sydney, New South Wales 2006, Australia.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Hernández-Prieto
authors.affiliation: Australian Research Council Centre of Excellence for Translational Photosynthesis and School of Biological Sciences, University of Sydney, New South Wales 2006, Australia.
authors.forename: Yuankui
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Australian Research Council Centre of Excellence for Translational Photosynthesis and School of Biological Sciences, University of Sydney, New South Wales 2006, Australia min.chen@sydney.edu.au.
authors.forename: Min
authors.identifier: 0000-0001-8070-3248
authors.initials: M
authors.lastname: Chen
mesh_terms: D002734:Chlorophyll / Q000235:genetics* / Q000378:metabolism; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D059014:High-Throughput Nucleotide Sequencing; D010100:Oxygen / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics; D014158:Transcription, Genetic; D059467:Transcriptome / Q000235:genetics*
chemical_list: D002734:Chlorophyll; D010100:Oxygen
keywords: chlorophyll biosynthesis; cyanobacteria; oxygen levels; reactive oxygen species; transcriptome response