In:
Limnology and Oceanography, Wiley, Vol. 58, No. 5 ( 2013-09), p. 1667-1679
Abstract:
We investigated the link between iron (Fe) limitation and intracellular dimethylsulfoniopropionate (DMSP) concentration in two oceanic phytoplankton species, the diatom Thalassiosira oceanica and the diazotrophic cyanobacterium Trichodesmium erythraeum . Dimethylsulfoxide (DMSO) concentrations were also measured in Fe‐replete and Fe‐limited T. oceanica . Fe limitation decreased the growth rates of T. oceanica and T. erythraeum by 33‐fold and 3.5‐fold, respectively and increased intracellular DMSP (DMSP p ) concentrations by 12‐fold (from 2.8 to 33.7 mmol L cell −1 ) and by 45‐fold (from 0.05 to 2.27 mmol L trichome −1 ), respectively. Intracellular dimethylsulfoxide (DMSO p ) concentrations in T. oceanica increased by 5‐fold under severe Fe limitation, from 0.78 mmol L cell −1 in Fe‐replete cells to 3.86 mmol L cell −1 . The increase in DMSP p and DMSO p under Fe limitation provides support for the role of these sulfur compounds as antioxidants. Under severe Fe limitation, the large increase in DMSP p : C and DMSP : chlorophyll a (Chl a ) ratios for both T. oceanica (by 16‐ and 40‐fold, respectively) and T. erythraeum (by 18‐ and 145‐fold, respectively) places these species above the range of values generally attributed to diatoms and cyanophytes. Comparison of these values with in situ results, such as those from Fe fertilization experiments, suggests that the decrease in DMSP p : Chl a and DMSO p : Chl a that is generally observed with alleviation of Fe limitation may be partly related to decreases in DMSP p and DMSO p in individual species. The role of diatoms and diazotrophic cyanobacteria in the biogeochemical cycle of dimethylsulfide and associated sulfur compounds in Fe‐limited oceanic environments should not be overlooked.
Type of Medium:
Online Resource
ISSN:
0024-3590
,
1939-5590
DOI:
10.4319/lo.2013.58.5.1667
Language:
English
Publisher:
Wiley
Publication Date:
2013
detail.hit.zdb_id:
2033191-5
detail.hit.zdb_id:
412737-7
SSG:
12
SSG:
14
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