ORIGINAL RESEARCH ARTICLE published: 02 November 2012 doi: 10.3389/fmicb.2012.00386
Nitrogenase (nifH) gene expression in diazotrophic cyanobacteria in the Tropical North Atlantic in response to nutrient amendments Kendra A. Turk-Kubo 1*, Katherine M. Achilles 1,2 , Tracy R. C. Serros 1 , Mari Ochiai 1,3 , Joseph P. Montoya 4 and Jonathan P. Zehr 1 1 2 3 4
Department of Ocean Sciences, University of California at Santa Cruz, Santa Cruz, CA, USA Southwest Fisheries Science Center, NOAA Fisheries Service, La Jolla, CA, USA Center for Marine Environmental Studies, Ehime University, Matsuyama, Ehime, Japan School of Biology, Georgia Institute of Technology, Atlanta, GA, USA
Edited by: Bess B. Ward, Princeton University, USA Reviewed by: Mark Moore, University of Southampton, UK Amal Jayakumar, Princeton University, USA *Correspondence: Kendra A. Turk-Kubo, Department of Ocean Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA. e-mail:
[email protected]
The Tropical North Atlantic (TNAtl) plays a critical role in the marine nitrogen cycle, as it supports high rates of biological nitrogen (N2 ) fixation, yet it is unclear whether this process is limited by the availability of iron (Fe), phosphate (P) or is co-limited by both. In order to investigate the impact of nutrient limitation on the N2 -fixing microorganisms (diazotrophs) in the TNAtl, trace metal clean nutrient amendment experiments were conducted, and the expression of nitrogenase (nifH) in cyanobacterial diazotrophs in response to the addition of Fe, P, or Fe+P was measured using quantitative PCR. To provide context, N2 fixation rates associated with the
