Phytoplankton antioxidant systems and their contributions to cellular elemental stoichiometry.

Oxidative stress plays a role in many aspects of cellular metabolism, and as a result, antioxidants have the potential to impact cellular stoichiometry and biogeochemical cycles. We reviewed how antioxidant systems influence macronutrient and micronutrient stoichiometry in marine phytoplankton and identified that antioxidant systems have important implications for micronutrient stoichiometry. By leveraging diatom proteomic data, we empirically estimated the level of micronutrient quota variation that can be attributed to antioxidant systems. Fe‐containing antioxidant expression may contribute to 3.3–10 μmol : mol variation in Fe : C, and superoxide dismutases appear to be important contributors to variation in Mn, Ni, Zn, and Cu quotas in phytoplankton. Critical next steps for the study of phytoplankton antioxidant systems are to (1) distinguish between oxidative stress and redox‐based gene regulation and (2) determine how antioxidants influence variation or consistency in micronutrient quotas under various environmental conditions. [ABSTRACT FROM AUTHOR]