Nitrogen and Iron Availability Drive Metabolic Remodeling and Natural Selection of Diverse Phytoplankton during Experimental Upwelling
Bethany C. Kolody, Sarah R. Smith, Lisa Zeigler Allen, John P. McCrow, Ahmed Moustafa, Dalin Shi, Brian M. Hopkinson, François M. M. Morel, Bess B. Ward, Andrew E. Allen
Abstract
Iron and nitrogen are the nutrients that most commonly limit phytoplankton growth in the world's oceans. The utilization of these resources by phytoplankton sets the biomass available to marine systems and is of particular interest in high-nutrient, low-chlorophyll (HNLC) coastal fisheries. Previous research has described the biogeography of phytoplankton in HNLC regions and the transcriptional responses of representative taxa to nutrient limitation. However, the differential transcriptional responses of whole phytoplankton communities to iron and nitrogen limitation has not been previously described, nor has the selective pressure that these competitive bloom environments exert on major players. In addition to describing changes in the physiology of diverse phytoplankton, we suggest practical indicators of cellular nitrogen and iron status for future monitoring.