{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE327nnn/GSE327000/"]},"type":"primary"},"statusCode":"OK","statusCodeValue":200}],"scores":null,"additional":{"omics_type":["Transcriptomics"],"species":["Parasynechococcus marenigrum WH 8102"],"gds_type":["Expression profiling by high throughput sequencing"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE327000"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"RNA-seq gene expression data for Synechococcus sp. WH8102 under continuous high, mid, and low phosphorus treatments in laboratory EFB experiments in 2025","description":"Polyphosphate (polyP) is a ubiquitous and evolutionarily conserved form of phosphorus (P) present in all living organisms, yet its role in cellular and biogeochemical P cycling remains poorly constrained. In P-depleted marine environments, polyP consistently represents a larger fraction of total particulate P (TPP) than in P-replete environments. This P deficiency response is paradoxical under the classical view of polyP as a luxury storage compound, highlighting a longstanding unresolved discrepancy. Whether the elevated polyP:TPP ratio reflects active accumulation under P stress or simply the persistence of this intracellular pool has never been directly tested under steady-state conditions. Using continuous cultures of the globally important marine cyanobacterium Synechococcus sp. WH8102, we address this knowledge gap. While P availability strongly affected growth rates, single-cell C:N:P stoichiometry and the expression of P-stress genes, polyP:TPP increased with decreasing growth rate, reproducing the pattern observed in oligotrophic marine environments. This shift was not driven by polyP accumulation; instead, cellular polyP concentrations remained relatively stable across growth rates (ANOVA, p = 0.16), while other intracellular P pools—including RNA, free Pi, ATP and phospholipids—were preferentially depleted with decreasing P availability (ranging from 2.6- to 11.8-fold, respectively), increasing the relative contribution of polyP to total cellular P. Gene expression analysis revealed little transcription differences between polyP-metabolism associated genes. These results indicate that cellular polyP content is maintained independently of growth rate under steady-state conditions, suggesting that P deficiency responses observed in oligotrophic environments and various microorganisms in batch culture reflect slow-growing physiology (differential pool lability over selective polyP retention), with consequences for interpreting particulate P stoichiometry and export.","dates":{"publication":"2026/05/05"},"accession":"GSE327000","cross_references":{"GSM":["GSM9645345","GSM9645344","GSM9645343","GSM9645342","GSM9645341","GSM9645340","GSM9645339","GSM9645338","GSM9645337"],"GPL":["36776"],"GSE":["327000"],"taxon":["Parasynechococcus marenigrum WH 8102"]}}