Limiting Nutrient Concentrations and Nutrient Assimilation and Storage Gene Expression across the Transition Zone Chlorophyll Front in the North Pacific Ocean

Abstract

This study investigates limiting nutrient-relevant cyanobacterial gene expression across the Transition Zone Chlorophyll Front (TZCF) in the north Pacific Ocean. An increase in available nutrients due to upwelling in the sub-arctic ocean gyre is expected to result in an increase in expression in genes associated with nutrient uptake and storage. This expected trend was not observed. Rather, there was a weak, negative correlation in all instances except ferritin expression in Synechococcus, which showed a weak positive correlation. The departure from the expected correlation is a likely a result of unexpected anthropogenic inputs of nutrients, or differences in nutrient usage among ecotypes of Prochlorococcus and Synechococcus.