Aquatic Sciences Meeting, Albuquerque 2001

SS16 Iron Bioavailability and Limitation to Primary Production (Disciplinary Connections)

Date: Monday, February 12, 2001, Time: 2:15:00 PM

Location: Mesilla

Maucher, J, M, University of Charleston, Charleston, USA, mauch1@hotmail.com

DiTullio, G, R, University of Charleston, Charleston, USA, ditullioj@cofc.edu

Rue, E, L, University of California Santa Cruz, Santa Cruz, USA, rue@cats.ucsc.edu

Bruland, K, W, University of California Santa Cruz, Santa Cruz, USA, bruland@cats.ucsc.edu

FLAVODOXIN AS A DIAGNOSTIC INDICATOR OF IRON STRESS IN THE EASTERN EQUATORIAL PACIFIC OCEAN

Iron limitation has been well documented in several high nutrient-low chlorophyll areas of the world's oceans, including the equatorial Pacific. The redox proteins flavodoxin (Flv) and ferredoxin (Fd) can be utilized as indicators of the iron nutritional status in marine phytoplankton; the former produced under iron stress and the latter under iron replete conditions. Research was conducted during the CHARYBDIS 2000 expedition to the eastern Equatorial Pacific to explore coastal upwelling regions off Peru as transitory areas of Fe limitation. HPLC analyses were performed to measure the relative amounts of Flv and Fd. In conjunction with dissolved iron concentrations, the ratio of % Flv: total soluble protein may be a valid indicator of the magnitude of iron stress in areas where Fd is undetectable. Size fractionation was used to assess prokaryotic and eukaryotic variability in Flv expression. On-deck incubation experiments were performed to determine the effects of Fe concentration on Flv synthesis. The potential of Flv as an in-situ diagnostic indicator of Fe limitation will be discussed.

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Aquatic Sciences Meeting, Albuquerque 2001

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