biostudies-literature00690Unknown7Walworth NGNitrogen fixation by cyanobacteria supplies critical bioavailable nitrogen to marine ecosystems worldwide; however, field and lab data have demonstrated it to be limited by iron, phosphorus and/or CO2. To address unknown future interactions among these factors, we grew the nitrogen-fixing cyanobacterium Trichodesmium for 1 year under Fe/P co-limitation following 7 years of both low and high CO2 selection. Fe/P co-limited cell lines demonstrated a complex cellular response including increased growth rates, broad proteome restructuring and cell size reductions relative to steady-state growth limited by either Fe or P alone. Fe/P co-limitation increased abundance of a protein containing a conserved domain previously implicated in cell size regulation, suggesting a similar role in Trichodesmium. Increased CO2 further induced nutrient-limited proteome shifts in widespread core metabolisms. Our results thus suggest that N2-fixing microbes may be significantly impacted by interactions between elevated CO2 and nutrient limitation, with broad implications for global biogeochemical cycles in the future ocean.Nature communications12081https://www.ebi.ac.uk/biostudies/studies/S-EPMC4931248biostudies-literatureMechanisms of increased Trichodesmium fitness under iron and phosphorus co-limitation in the present and future ocean.PMC4931248Fu FXMcllvin MRLee MDWebb EAWalworth NGHutchins DAMoran DSaito MA69falseMechanisms of increased Trichodesmium fitness under iron and phosphorus co-limitation in the present and future ocean.Nitrogen fixation by cyanobacteria supplies critical bioavailable nitrogen to marine ecosystems worldwide; however, field and lab data have demonstrated it to be limited by iron, phosphorus and/or CO2. To address unknown future interactions among these factors, we grew the nitrogen-fixing cyanobacterium Trichodesmium for 1 year under Fe/P co-limitation following 7 years of both low and high CO2 selection. Fe/P co-limited cell lines demonstrated a complex cellular response including increased growth rates, broad proteome restructuring and cell size reductions relative to steady-state growth limited by either Fe or P alone. Fe/P co-limitation increased abundance of a protein containing a conserved domain previously implicated in cell size regulation, suggesting a similar role in Trichodesmium. Increased CO2 further induced nutrient-limited proteome shifts in widespread core metabolisms. Our results thus suggest that N2-fixing microbes may be significantly impacted by interactions between elevated CO2 and nutrient limitation, with broad implications for global biogeochemical cycles in the future ocean.2016-01-01T00:00:00Z2016 Jun2021-02-20T20:59:20Z2019-03-27T02:17:26ZS-EPMC49312482734642010.1038/ncomms12081