Coordinated Regulation of Growth, Activity and Transcription In Natural Populations of the Unicellular Nitrogen-Fixing Cyanobacterium Crocosphaera

Authors

Samuel T. Wilson, University of HawaiiFollow
Frank O. Aylward, University of Hawaii
Francois Ribalet, University of Washington
Benedetto Barone, University of Hawaii
John R. Casey, University of Hawaii
Paige E. Connell, University of Southern California, Los Angeles
John M. Eppley, University of Hawaii
Sara Ferrón, University of Hawaii
Jessica N. Fitzsimmons, Texas A&M UniversityFollow
Christopher T. Hayes, University of Southern MississippiFollow
Anna E. Romano, University of Hawaii
Kendra A. Turk-Kubo, University of California, Santa Cruz
Alice Vislova, University of Hawaii
E. Virginia Armbrust, University of Washington
David A. Caron, University of Southern California, Los Angeles
Matthew J. Church, University of HawaiiFollow
Jonathan P. Zehr, University of California, Santa Cruz
David M. Karl, University of HawaiiFollow
Edward F. DeLong, University of Hawaii

Document Type

Article

Publication Date

7-31-2017

Department

Marine Science

School

Ocean Science and Engineering

Abstract

The temporal dynamics of phytoplankton growth and activity have large impacts on fluxes of matter and energy, yet obtaining in situ metabolic measurements of sufficient resolution for even dominant microorganisms remains a considerable challenge. We performed Lagrangian diel sampling with synoptic measurements of population abundances, dinitrogen (N₂) fixation, mortality, productivity, export and transcription in a bloom of Crocosphaera over eight days in the North Pacific Subtropical Gyre (NPSG). Quantitative transcriptomic analyses revealed clear diel oscillations in transcript abundances for 34% of Crocosphaera genes identified, reflecting a systematic progression of gene expression in diverse metabolic pathways. Significant time-lagged correspondence was evident between nifH transcript abundance and maximal N₂ fixation, as well as sepF transcript abundance and cell division, demonstrating the utility of transcriptomics to predict the occurrence and timing of physiological and biogeochemical processes in natural populations. Indirect estimates of carbon fixation by Crocosphaera were equivalent to 11% of net community production, suggesting that under bloom conditions this diazotroph has a considerable impact on the wider carbon cycle. Our cross-scale synthesis of molecular, population and community-wide data underscores the tightly coordinated in situ metabolism of the keystone N₂-fixing cyanobacterium Crocosphaera, as well as the broader ecosystem-wide implications of its activities.

Publication Title

Nature Microbiology

Volume

2

First Page

1

Last Page

9

Recommended Citation

Wilson, S. T., Aylward, F. O., Ribalet, F., Barone, B., Casey, J. R., Connell, P. E., Eppley, J. M., Ferrón, S., Fitzsimmons, J. N., Hayes, C. T., Romano, A. E., Turk-Kubo, K. A., Vislova, A., Armbrust, E., Caron, D. A., Church, M. J., Zehr, J. P., Karl, D. M., DeLong, E. F. (2017). Coordinated Regulation of Growth, Activity and Transcription In Natural Populations of the Unicellular Nitrogen-Fixing Cyanobacterium Crocosphaera. Nature Microbiology, 2, 1-9.
Available at: https://aquila.usm.edu/fac_pubs/16663