AME 86:29-46 (2021)  -  DOI: https://doi.org/10.3354/ame01955

ABSTRACT: Phosphorus (P) limits primary production in regions of the surface ocean, and many plankton species exhibit specific physiological responses to P deficiency. The metabolic response of Micromonas pusilla, an ecologically relevant marine photoautotroph, to P deficiency was investigated using metabolomics and comparative genomics. The concentrations of some intracellular metabolites were elevated in the P-deficient cells (e.g. xanthine, inosine), and genes involved in the associated metabolic pathways shared a predicted conserved amino acid motif in the non-coding regions of each gene. The presence of the conserved motif suggests that these genes may be co-regulated, and the motif may constitute a regulatory element for binding a transcription factor, specifically that of Psr1 (phosphate starvation response). A putative phosphate starvation response gene ( psr1-like) was identified in M. pusilla with homology to well characterized psr1/ phr1 genes in algae and plants, respectively. This gene appears to be present and expressed in other marine algal taxa (e.g. Emiliania huxleyi) in field sites that are chronically P limited. Results from the present study have implications for understanding phytoplankton taxon-specific roles in mediating P cycling in the ocean.

KEY WORDS: Micromonas pusilla · Phosphate stress response · Marine algae · Metabolomics · Dissolved organic matter · Biological oceanography

Full text in pdf format Supplement 1 Supplement 2

Cite this article as: Fiore CL, Alexander H, Kido Soule MC, Kujawinski EB (2021) A phosphate starvation response gene ( psr1-like) is present and expressed in Micromonas pusilla and other marine algae. Aquat Microb Ecol 86:29-46. https://doi.org/10.3354/ame01955 Export citation Share:    Facebook - - linkedIn