Interactions between Thermal Acclimation, Growth Rate, and Phylogeny Influence Prochlorococcus Elemental...

Area of Science:

• Marine microbial ecology
• Biogeochemical cycles
• Phytoplankton physiology

Background:

• Plankton elemental composition (C/N/P ratios) is crucial for ocean biogeochemistry.
• The influence of ocean temperature on these ratios is not fully understood.
• Existing hypotheses, like 'translation-compensation,' suggest temperature increases N/P and C/P ratios.

Purpose of the Study:

• To investigate the direct and indirect effects of ocean temperature on plankton elemental composition.
• To test the 'translation-compensation' hypothesis in marine cyanobacteria.
• To assess how temperature influences carbon, nitrogen, and phosphorus cell quotas.

Main Methods:

• Analyzed elemental composition (C, N, P) and ratios in six strains of Prochlorococcus.
• Experimentally manipulated ocean temperature and growth rates.
• Examined strain-specific responses to temperature and growth rate variations.

Main Results:

• Temperature significantly increased carbon and nitrogen cell quotas in Prochlorococcus.
• No clear trend was observed for phosphorus cell quotas.
• N/P and C/P ratios showed marginally significant positive trends, but individual strain responses varied complexly with temperature and growth rate.

Conclusions:

• The 'translation-compensation' theory was not supported by these findings.
• Rising ocean temperatures may induce unique cellular elemental effects in phytoplankton.
• Biodiversity must be considered when predicting future elemental ratios and biogeochemical cycles in the ocean.