Prevention of stress in iron metabolism of plants

Bienfait, H. Frits

doi:10.1111/j.1438-8677.1989.tb02035.x

Cited by 104 publications

(57 citation statements)

References 194 publications

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“…Fe, this situation is likely to be a reason for heavyFrom the shape of the curves in Figure 1 it is metal-induced Fe deficiency in heavy-metal-rich tempting to suggest that Fe^+ ions are hindered in soils. reaching a specific binding site in the cytoplasm, as After intact plants were transferred to chelate-free proposed by Bienfait (1989), resulting in decreased medium containing S piM CuSO^, the reduction repression of the reductase. A putative repressor of activity of -Fe plants was almost totally inhibited the Fe-deficiency response might remain unsatu-within 20 min (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Defects in Fe inhibition of mobilization, uptake and/or trans-metabolism were considered to be the cause of location of Fe. Homeostatic control of iron uptake in increased Cu uptake and the chlorotic phenotype of Strategy I plants is achieved by the activity of root-the cupl-1 mutant of Arabidopsis thaliana supplied associated Fe(III) reductase (Bienfait, 1989; with suboptimal levels of Cu (Van Vliet, Andersen & Marschner & Romheld, 1994), and, thus, inhibition Cobbett, 1995. Iron chlorosis induced by excess Cu of extractyoplasmic reduction of Fe might account might or might not be accompanied by decreased Fe for this heavy-metal-induced chlorosis.…”

Section: Introductionmentioning

confidence: 99%

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Physiological effects of copper on iron acquisition processes in Plantago

et al. 1997

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(This paper is dedicated to the memory of Professor Horst Marschner) SUMMARY In Plantago lanceolata L. the effect of Cu(II) additions to the nutrient solution on root-associated Fe(III) reductase was studied in a factorial design with different Cu(II) and Fe(III) concentrations. Iron starvation resulted in approx. an eightfold increase in root Fe reduction at the level of intact plants and twofold enhancement in the specific activity of both NADH-linked FeEDTA reductase and H^-ATPase in isolated root plasma membrane vesicles. In plants exposed to low (0-3-0-7 /iM) Cu and suboptimal Fe levels, reduction activity at the root surface was further increased and associated with more severe interveinal chlorosis than plants grown in Cufree medium. In Fe-sufficient plants, withholding Cu over a prolonged period slightly enhanced the reduction activity.Addition of high (5 fiM) Cu concentrations to Fe-free medium inhibited the induction of the physiological responses by Fe-deficiency stress. In plants without Fe supply but with adequate Cu supply, short-term application of 5 /iM CuSO^ completely inhibited the reduction activity. Neither incubation of the plasma membrane vesicles before measurement nor incubation of intact plants with Cu before isolation caused a significant decrease in reductase activity. The results are interpreted as indicating different mechanisms underlying Cu-induced alterations in iron nutrition.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physiological effects of copper on iron acquisition processes in Plantago

et al. 1997

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“…Some diffuses out of the root radially, thereby re-oxidizing the first thin layer around the roots in the otherwise anaerobic soil (Smits et al, 1990;Laan et al, 1989/?). The benefit of this phenomenon to the plant is the immobilization of resulting metal ions such as Fe2f and M n2+, which become toxic for the plant when in its chemically reduced and thus insoluble form (Bienfait, 1989;Laan et al, 1989/? ;Ernst, 1990;Laan, Smolders and Blom, 1991«).…”

Section: Adventitious Root Formation Functionality Of the Renewed Romentioning

confidence: 99%

“…) and the accelerated growth, underwater, of stems and petioles ,/? ; Perik et a i, 1989;Voesenek et al, 1990Voesenek et al, , 1992Voesenek et al, , 1993. This paper examines mechanisms of these adaptative reactions in order to understand more about the con tribution of these responses to distribution, maintenance and survival of plants during the adverse conditions of the submergence period in the field.…”

Section: Introductionmentioning

confidence: 99%

Physiological Ecology of Riverside Species: Adaptive Responses of Plants to Submergence

Blom

1994

Annals of Botany

149

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In river floodplains, variation in flooding conditions results in successional stages in colonization ranging from annual pioneers to long-lived perennials. Reactions to submergence of species from the mid-successional zone are compared with adaptive responses of species from other zones. Presence and abundance are related to elevation and can be explained by characteristics of biomass production, and recovery in response to various submergence intensities.Rume.x species, from early to late successional stages, serve as models to elucidate, in more detail, mechanisms of adaptation. Flooding-resistant species develop large numbers of adventitious roots upon submergence and exposure to low oxygen conditions. Due to internal oxygen transport through aerenchyma, soil around these roots is re oxidized, which stimulates bacterial nitrification. Ethylene and auxin promote adventitious rooting. Increased petiole elongation is also an adaptive feature of submergence-resistant Rume.x species. Differences between species in submergence-induced growth are not only controlled by variation in endogenous levels of ethylene but also by different sensitivities to this hormone. Auxin does not affect Rume.x petiole elongation, but a clear positive effect of gibberellin is demonstrated. Apparently, submergence induces a higher sensitivity to gibberellin and ethylene in the petioles of flooding-resistant Rume.x. Many of the submergence reactions can also be induced by restricting the oxygen supply, suggesting that low-oxygen might be a triggering factor. The Rume.x species we study represent various distinct communities. Thus, the ecophysiological phenomena observed in these model plants may explain processes and patterns in other species too and thus are interpretable at the riverside community level.

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“…In dicotyledonous and non-grass monocotyledonous plants, these responses include acidification of the rhizosphere, enhanced reduction of ferric chelates and release of reducing and\or chelating low-molecular-weight compounds (Strategy I, Marschner & Ro$ mheld (1994)). Adaptation to high Fe concentrations might be achieved by Fe-excluding mechanisms such as reoxidation of Fe# + and concomitant precipitation or internal detoxification (Bienfait, 1989).…”

Section: mentioning

confidence: 99%

Sensitivity to and requirement for iron in Plantago species

Schmidt

Fühner

1998

New Phytologist

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The relative importance of some aspects of iron nutrition for the distribution of six Plantago species (P. maritima L., P. coronopus L., P. major ssp. major L., P. serpentina All., P. media L. and P. lanceolata L.) with different habitat requirements for soil pH and moisture was evaluated. Iron efficiency and Fe tolerance of hydroponicallygrown plants were assessed by determining the decrease in relative growth rates caused by suboptimal and supraoptimal external Fe concentrations. Marked interspecific differences were observed in visual symptoms of Fe deficiency and Fe toxicity and in the external Fe concentrations leading to 50 % inhibition of maximal relative growth rates ( &! % ). Whereas P. serpentina displayed a clear preference for low external Fe concentrations, growth rates of P. maritima and P. media were found to be increased at higher concentrations. Severe growth restriction at both low and high Fe concentrations was evident in P. lanceolata and P. major. A broad optimum was observed in P. coronopus exhibiting a low external Fe requirement and a high tolerance to supra-optimal Fe concentrations. Iron efficiency and Fe tolerance differed in a way which was only partly correlated with the expected Fe availability at the natural habitat of the species, suggesting that Fe concentrations are of minor importance for their distribution, or that some of the mechanisms that render Fe oxides available for uptake in situ are masked in solution experiments.To gain insight into the impact of the physiological and morphological characteristics of the species on Fe efficiency, the effect of Fe status on shoot : root ratio, relative root surface area, root Fe(III) reductase and proton extrusion capacity were investigated. Roots of all species showed increased Fe chelate reduction activity upon growth at suboptimal Fe concentrations ; marked differences were observed with respect to the kinetic parameters of the reductase. Maximal velocity of the reduction was positively correlated with relative growth rate and was not related to the Fe efficiency of the species. By contrast, K m corresponded to Fe efficiency ranking and can therefore be regarded as an important parameter for the uptake of Fe at low availability. Enhanced ability to acidify the rhizosphere was only observed in P. major. From the morphological characteristics investigated, root surface area appears to be the most important parameter in the uptake of Fe at suboptimal external concentrations.

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Prevention of stress in iron metabolism of plants

Cited by 104 publications

References 194 publications

Physiological effects of copper on iron acquisition processes in Plantago

Physiological effects of copper on iron acquisition processes in Plantago

Physiological Ecology of Riverside Species: Adaptive Responses of Plants to Submergence

Sensitivity to and requirement for iron in Plantago species

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