Divergent responses of Atlantic coastal and oceanic Synechococcus to iron limitation
Mackey, Katherine R. M.
Post, Anton F.
McIlvin, Matthew R.
Cutter, Gregory A.
John, Seth G.
Saito, Mak A.
MetadataShow full item record
Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet utilized few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multi-tiered, hierarchical cascade of acclimation responses with different Fe thresholds. The multi-tiered response included changes in Fe acquisition, storage, and photosynthetic proteins, substitution of flavodoxin for ferredoxin, and modified photophysiology, all while maintaining remarkably stable growth rates over a range of Fe concentrations. Modulation of two distinct ferric uptake regulator (Fur) proteins that coincided with the multi-tiered proteome response was found, implying the coastal strain has different regulatory threshold responses to low Fe availability. Low nitrogen (N) and phosphorus (P) availability in the open ocean may favor the loss of Fe response genes when Fe availability is consistent over time, whereas these genes are retained in dynamic environments where Fe availability fluctuates and N and P are more abundant.
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 112 (2015): 9944-9949, doi:10.1073/pnas.1509448112.
Showing items related by title, author, creator and subject.
Saito, Mak A.; Rocap, Gabrielle; Moffett, James W. (2005)The Costa Rica upwelling dome (CRD; ~8.67ºN and 90.6ºW) was characterized chemically for cobalt and nickel abundances and speciation, and biologically using cyanobacterial abundances and phylogeny. Total dissolved cobalt ...
Iron stress in open-ocean cyanobacteria (Synechococcus, Trichodesmium, and Crocosphaera spp.) : identification of the IdiA protein Webb, Eric A.; Moffett, James W.; Waterbury, John B. (American Society for Microbiology, 2001-12)Cyanobacteria are prominent constituents of the marine biosphere that account for a significant percentage of oceanic primary productivity. In an effort to resolve how open-ocean cyanobacteria persist in regions where the ...
Boiteau, Rene M.; Repeta, Daniel J. (2015-03-11)Siderophores are thought to play an important role in iron cycling in the ocean, but relatively few marine siderophores have been identified. Sensitive, high throughput methods hold promise for expediting the discovery ...