title: Iron uptake mechanism in the chrysophyte microalga Dinobryon.
abstract: The mechanism of iron uptake in the chrysophyte microalga Dinobryon was studied. Previous studies have shown that iron is the dominant limiting elements for growth of Dinobryon in the Eshkol reservoir in northern Israel, which control its burst of bloom. It is demonstrated that Dinobryon has a light-stimulated ferrireductase activity, which is sensitive to the photosynthetic electron transport inhibitor DCMU and to the uncoupler CCCP. Iron uptake is also light-dependent, is inhibited by DCMU and by CCCP and also by the ferrous iron chelator BPDS. These results suggest that ferric iron reduction by ferrireductase is involved in iron uptake in Dinobryon and that photosynthesis provides the major reducing power to energize iron acquisition. Iron deprivation does not enhance but rather inhibits iron uptake contrary to observations in other algae.
authors: Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel.
authors: Nava
authors: N
authors: Carmel
authors: Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel. Electronic address: telor@agri.huji.ac.il.
authors: Elisha
authors: E
authors: Tel-Or
authors: Department of Soil and Water Sciences, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel.
authors: Yona
authors: Y
authors: Chen
authors: Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: uri.pick@weizmann.ac.il.
authors: Uri
authors: U
authors: Pick
mesh_terms: D044523:Chrysophyta / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D003470:Culture Media / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038181:FMN Reductase / Q000037:antagonists & inhibitors / Q000378:metabolism; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D008027:Light; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D010618:Phenanthrolines / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D013997:Time Factors
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D010618:Phenanthrolines; C017049:bathophenanthroline disulfonic acid; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase
keywords: Dinobryon; Enzyme activity; Ferrireductase; Growth pattern; Iron uptake