ISSN:
1573-5036
Keywords:
cycloheximide
;
ferric reduction
;
p-fluorophenylalanine
;
plasmalemma redox systems
;
Plantago lanceolata
;
plant iron nutrition
;
protein synthesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Roots of Plantago lanceolata L. showed an iron stress-induced increase in the rates of electron transport to the extracytoplasmatic acceptors FeEDTA and ferricyanide. No significant changes in the reduction of hexachloroiridate were observed with respect to the iron-nutritional status of the plants. The reduction activity of iron-deficient roots was inhibited by the translation inhibitor cycloheximide (CHM) and the amino acid analog p-fluorophenylalanine (FPA). In both cases, the reduction of FeEDTA and ferricyanide was affected to a different extent, providing evidence for enzyme heterogeneity. Resupply of FeEDTA to iron-deficient plants resulted in a qualitatively similar pattern of decrease in FeEDTA and ferricyanide reduction rates, although a longer time period was required for the decrease of the redox activity by iron resupply compared to the effect of inhibitors of protein synthesis. Inhibitors of the plasma membrane (PM)-bound H+-ATPase decreased the FeEDTA reduction activity of iron-deficient plants. In contrast, the reduction of ferricyanide and hexachloroiridate was not inhibited. Oxidation of ferrocyanide occurs in both iron-deficient and iron-sufficient plants at comparable rates. The reaction was decreased by the H+-ATPase inhibitor orthovanadate. The results are interpreted in terms of a simultaneous action of distinct redox systems in iron-deficient roots. The role of proton extrusion in the regulation of iron stress-induced electron transport is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00008063
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