Co-occurrence of Fe and P stress in natural populations of the marine diazotroph Trichodesmium
Name
bg-17-2537-2020.pdf
Description
Published version
Size
4.3 MB
Format
Adobe PDF
Checksum (MD5)
4f9abe011f947dba4121c20d80cee223
Author(s)
Held, Noelle A
Webb, Eric A
McIlvin, Matthew M
Hutchins, David A
Cohen, Natalie R
Moran, Dawn M
Kunde, Korinna
Lohan, Maeve C
Mahaffey, Claire
Woodward, E Malcolm S
Date Issued
May 12, 2020
Journal
Biogeosciences
Publisher
Copernicus GmbH
Citation
Held, N. A., Webb, E. A., McIlvin, M. M., Hutchins, D. A., Cohen, N. R., Moran, D. M., Kunde, K., Lohan, M. C., Mahaffey, C., Woodward, E. M. S., and Saito, M. A.: Co-occurrence of Fe and P stress in natural populations of the marine diazotroph Trichodesmium, Biogeosciences, 17, 2537–2551.
Version
Final published version
Abstract
Trichodesmium is a globally important marine microbe that provides fixed nitrogen (N) to otherwise N-limited ecosystems. In nature, nitrogen fixation is likely regulated by iron or phosphate availability, but the extent and interaction of these controls are unclear. From metaproteomics analyses using established protein biomarkers for nutrient stress, we found that iron–phosphate co-stress is the norm rather than the exception for Trichodesmium colonies in the North Atlantic Ocean. Counterintuitively, the nitrogenase enzyme was more abundant under co-stress as opposed to single nutrient stress. This is consistent with the idea that Trichodesmium has a specific physiological state during nutrient co-stress. Organic nitrogen uptake was observed and occurred simultaneously with nitrogen fixation. The quantification of the phosphate ABC transporter PstA combined with a cellular model of nutrient uptake suggested that Trichodesmium is generally confronted by the biophysical limits of membrane space and diffusion rates for iron and phosphate acquisition in the field. Colony formation may benefit nutrient acquisition from particulate and organic sources, alleviating these pressures. The results highlight that to predict the behavior of Trichodesmium, both Fe and P stress must be evaluated simultaneously.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.5194/bg-17-2537-2020
