Distributions of Particulate Heme b in the Atlantic and Southern Oceans- Implications for Electron Transport in Phytoplankton

• Published in: Global Biogeochemical Cycles
• Main Authors: Gledhill, Martha, Achterberg, Eric P., Honey, David J., Nielsdottir, Maria C., Rijkenberg, Micha J.A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ODU Digital Commons 2013
• Subjects: Iron; Phytoplankton; Physiology; Nutrients; Biogenic particulate material; Atlantic Ocean; Microplankton community structure; Scotia sea; Iron availability; Tetrapyrrole biosynthesis; Marine phytoplankton; North atlantic; Spring bloom; Photosynthesis; Diatom; Dust; Biochemistry; Geology; Oceanography and Atmospheric Sciences and Meteorology; Scotia Sea; North Atlantic
• Online Access: https://digitalcommons.odu.edu/oeas_fac_pubs/263; https://doi.org/10.1002/2013gb004639; https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1271/viewcontent/Nielsdottir2013DistributionsofparticulateHemebintheAtlanticOCR.pdf

Concentrations of heme b, the iron-containing component of b-type hemoproteins, ranged from b concentrations were enhanced in the photic zone and decreased with depth. Heme b concentrations correlated positively with chlorophyll a (chl a) in the TNA (r=0.41, pb did not correlate with chl a in the IB or SS. In the IB and SS, stations with high-chlorophyll and low-nutrient (Fe and/or Si) concentrations exhibited low heme bconcentrations relative to particulate organic carbon (< 0.1 μmolmol-1, and high chl a:heme b ratios (> 500). High chl a:heme b ratios resulted from relative decreases in heme b, suggesting proteins such as cytochrome b6f, the core complex of photosystem II, and eukaryotic nitrate reductase were depleted relative to proteins containing chlorophyll such as the eukaryotic light-harvesting antenna. Relative variations in heme b, particulate organic carbon, and chl a can thus be indicative of a physiological response of the phytoplankton community to the prevailing growth conditions, within the context of large-scale changes in phytoplankton community composition.