Copper Toxicity Affects Photosystem II Electron Transport at the Secondary Quinone Acceptor, Q<sub>B</sub>

Mohanty, N.; Vass, Imre; Demeter, S.

doi:10.1104/pp.90.1.175

Cited by 132 publications

(72 citation statements)

References 22 publications

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“…These data are in accordance with those reported by other authors (Shioi et al 1978b, Bohner et al 1980. Hsu and Lee 1988, Samson et al 1988, Mohanty et al 1989. A 50% inhibition of Fv occurred in the presence of ~20 μM CuCl 2 , whereas only~7 30% of PSII are able to emit variable fluorescence after treatment with 40 μM , that could correspond to the extrinsic proteins that stabilise the oxygen-evolving complex and regulare its activity (Enami et al 1989, Hankamer and Barber 1997.…”

Section: Resultssupporting

confidence: 82%

“…Both the acceptor and donor side have been proposed as copper-inhibitory sites. On the PSII reducing side, the Q B binding site (Mohanty et al 1989) and the Pheo-Fe-Q A , domain (Yruela et al 1991(Yruela et al , 1992(Yruela et al , 1993(Yruela et al , 1996a have been reported as the most sensitive sites for Cu(II) toxicity. In addition, the copper ion was shown to impair the function of the oxidising side ( Cedeño-Maldonado and Swader 1972, Vierke and Struckmeier, 1977, Shioi et al 1978a,b, Bohner et al 1980, Samuelsson and Öquist 1980.…”

Section: Introductionmentioning

confidence: 99%

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Copper effect on the protein composition of photosystem II

et al. 2000

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We provide data from in vitro experiment on the polypeptide composition, photosynthetic electron transport and oxygen evolution activity of intact photosystem II (PSII) preparations under Cu(II) toxicity conditions. Low Cu(II) concentrations (Cu(II) per PSII reaction centre unit < 230) that caused around 50% inhibition of variable chlorophyll a fluorescence and oxygen evolution activity did not affect the polypeptide composition of PSII. However, the extrinsic proteins of 33, 24 and 17 kDa of the oxygen-evolving complex of PSII were removed when samples were treated with 300 μM CuCl 2 (Cu(II) per PSII reaction centre unit = 1400). The LHCII antenna complex and D1 protein of the reaction centre of PSII were not affected at these Cu(II) concentrations. The results indicated that the initial inhibition of the PSII electron transport and oxygen-evolving activity induced by the presence of toxic Cu(II) concentrations occurred before the damage of the oxygen-evolving complex. Indeed, more than 50% inhibition could be achieved in conditions where its protein composition and integrity was apparently preserved.

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Section: Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Copper effect on the protein composition of photosystem II

et al. 2000

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“…DF has been used in research of metals' effects on photosynthesis of algae and higher plants [19,25,26]. Simple, reliable and rapid measurements as well as minimal sample manipulation, e.g.…”

Section: Introductionmentioning

confidence: 99%

Delayed fluorescence in algal growth inhibition tests

et al. 2007

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A series of 72-hour growth inhibition tests with green alga Desmodesmus (Scenedesmus) subspicatus (ISO 8692) has been performed to test the delayed fluorescence (DF) parameters as possible endpoint measurements. Sensitivity to five toxicants with direct and indirect effects on photosynthesis was tested, and the median effective concentration (EC 50 ) values derived from the cell concentration, absorbance and DF were compared. The sensitivity of DF intensity (DFI) was comparable with the two endpoints suggested in ISO 8692 for all five toxicants: potassium dichromate, 3,5-dichlorophenol (3,5-DCP), DCMU, copper and cadmium. In the case of potassium dichromate and copper, DFI was more sensitive than the other endpoints in this study. The analysis of DF relaxation kinetics showed a specific response to the herbicide DCMU. Additionally, a 24-hour test was performed with the same toxicant concentrations (except copper), where DFI was measured 30 minutes, one hour and 24 hours after the exposure. The influence of toxicants on DFI after a 24-hour exposure was comparable with the effects after 72 hours. Only 3,5-DCP influenced DFI after 30 minutes. DF proved to be a simple, reliable and rapid measurement to assess toxicity in algal tests, which can to some extent differentiate among various toxicants.

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“…Most authors relate the target of the Cu-inhibition of PSII to its oxidizing side [7,54,55]. At higher copper concentrations, primary quinone acceptor QA [27], pheophytin-QA-Fe region [70], non-haem iron [28], and secondary quinone acceptor QB [44] were identifed as the target sites of Cu inhibitory action on the acceptor side of PSII (Fig. 4).…”

Section: Plants and Algaementioning

confidence: 99%

Copper and Copper-Containing Pesticides: Metabolism, Toxicity and Oxidative Stress

Husak

2015

jpnu

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Abstract. The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals), because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD), and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

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Copper Toxicity Affects Photosystem II Electron Transport at the Secondary Quinone Acceptor, Q_B

Abstract: The nature of Cu2+ inhibition of photosystem 11 (PSII)

Cited by 132 publications

References 22 publications

Copper effect on the protein composition of photosystem II

Copper effect on the protein composition of photosystem II

Delayed fluorescence in algal growth inhibition tests

Copper and Copper-Containing Pesticides: Metabolism, Toxicity and Oxidative Stress

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Copper Toxicity Affects Photosystem II Electron Transport at the Secondary Quinone Acceptor, QB

Abstract: The nature of Cu2+ inhibition of photosystem 11 (PSII)

Cited by 132 publications

References 22 publications

Copper effect on the protein composition of photosystem II

Copper effect on the protein composition of photosystem II

Delayed fluorescence in algal growth inhibition tests

Copper and Copper-Containing Pesticides: Metabolism, Toxicity and Oxidative Stress

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Product

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Copper Toxicity Affects Photosystem II Electron Transport at the Secondary Quinone Acceptor, Q_B