NADP-malate Dehydrogenase Activity during Photosynthesis in Illuminated Spinach Chloroplasts

Scheibe, Renate; Wagenpfeil, D.; Fischer, Jan‐Patrick

doi:10.1016/s0176-1617(86)80182-1

Cited by 24 publications

(7 citation statements)

References 18 publications

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“…This is in accordance with data from Rao and Anderson (1983), Gotow et al (1985a) and Sharkey and Ogawa (1987) and can be explained on the basis of a light-activated NADP-malate dehydrogenase which metabolizes oxaloacetic acid to malate (Gotow et al 1985b;Scheibe et al 1986).…”

Section: Discussionsupporting

confidence: 91%

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Michalke¹,

Schnabl

1990

Planta

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Phosphoenolpyruvate carboxylase (PEPCase; EC 4.1.1.31) activity was found to be modulated by light and darkness when measured in the presence of K(+), which had been added to induce swelling of guard-cell protoplasts (GCPs) from Vicia faba L., whereas no modulation was detected in the absence of K(+) (PEPcase activity remained constant at 1.5±0.15 pmol PEP metabolized · GCP(-1) ·h(-1); subsequently, pmol GCP(-1) ·h(-1) will be used). The activity of PEPCase increased by 100% (from 1.5 to 3 pmol·protoplast(-1)·h(-1)) in darkness and by 200% (from 1.7 to 5 pmol·protoplast(-1)· h(-1)) in light and oscillations in activity of these magnitudes were repeated at intervals of 2 min (dark) and 2.5 min (light) for a period of 10 min during K(+)-induced increase in the volume of GCPs. The oscillations were reflected in changes in malate-pool sizes determined in plastids, mitochondria and the supernatant fraction (consisting of the cytosol and the vacuole). Malate probably functioned as a mitochondrial substrate, thus supplying ATP for K(+) uptake and the swelling of the protoplasts. On the basis of the present paper and previous results (H. Schnabl and B. Michalke 1988, Life Sci. Adv. Plant Physiol. 7, 203-207) involving adenine nucleotidepool sizes in fractionated GCPs, a model is proposed to explain the cause-effect relationship between K(+), PEPCase, the cytosolic and mitochondrial malate levels and ATP levels during the K(+)-induced increase of GCP volume.

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Section: Discussionsupporting

confidence: 91%

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Michalke¹,

Schnabl

1990

Planta

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“…In photosynthesizing leaves, malate participates in shuttling reductive equivalents from chloroplasts to cytosol via a malate/OAA shuttle, maintaining the necessary balance between chloroplastic NADPH and ATP levels (Scheibe et al, 1986;Scheibe, 1987;Fig. 6).…”

Section: Effects Of the Pepc Inhibitor Doa On Foliage Photosynthesis mentioning

confidence: 99%

“…6). Chloroplastic malate accumulation is expected to result in an enhanced chloroplastic NADPH/NADP + ratio as the result of reversal of the malate dehydrogenase reaction toward OAA synthesis and shutting off the malate valve that transports excess reductive equivalents to cytosol (Scheibe et al, 1986;Scheibe, 1987;Backhausen et al, 1994Backhausen et al, , 2000Fig. 6).…”

Section: Effects Of the Pepc Inhibitor Doa On Foliage Photosynthesis mentioning

confidence: 99%

Evidence That Isoprene Emission Is Not Limited by Cytosolic Metabolites. Exogenous Malate Does Not Invert the Reverse Sensitivity of Isoprene Emission to High [CO₂]

et al. 2017

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Isoprene is synthesized via the chloroplastic 2--methyl-d-erythritol 4-phosphate/1-deoxy-d-xylulose 5-phosphate pathway (MEP/DOXP), and its synthesis is directly related to photosynthesis, except under high CO concentration, when the rate of photosynthesis increases but isoprene emission decreases. Suppression of MEP/DOXP pathway activity by high CO has been explained either by limited supply of the cytosolic substrate precursor, phosphopyruvate (PEP), into chloroplast as the result of enhanced activity of cytosolic PEP carboxylase or by limited supply of energetic and reductive equivalents. We tested the PEP-limitation hypotheses by feeding leaves with the PEP carboxylase competitive inhibitors malate and diethyl oxalacetate (DOA) in the strong isoprene emitter hybrid aspen ( × ). Malate feeding resulted in the inhibition of net assimilation, photosynthetic electron transport, and isoprene emission rates, but DOA feeding did not affect any of these processes except at very high application concentrations. Both malate and DOA did not alter the sensitivity of isoprene emission to high CO concentration. Malate inhibition of isoprene emission was associated with enhanced chloroplastic reductive status that suppressed light reactions of photosynthesis, ultimately leading to reduced isoprene substrate dimethylallyl diphosphate pool size. Additional experiments with altered oxygen concentrations in conditions of feedback-limited and non-feedback-limited photosynthesis further indicated that changes in isoprene emission rate in control and malate-inhibited leaves were associated with changes in the share of ATP and reductive equivalent supply for isoprene synthesis. The results of this study collectively indicate that malate importantly controls the chloroplast reductive status and, thereby, affects isoprene emission, but they do not support the hypothesis that cytosolic metabolite availability alters the response of isoprene emission to changes in atmospheric composition.

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“…The activity of enzyme measured immediately accounted for initial (non-activated) activity, while total activity was measured after complete activation of enzyme by incubating chloroplast suspension with 20 mM dithiothreitol at pH 8.0 at room temperature. The final activity was expressed as the ratio of initial to total activity (activated) (Scheibe et al, 1986).…”

Section: Measurement Of Pyridine Nucleotides: Nadpmentioning

confidence: 99%

Photosynthetic performance of Salvinia natans exposed to chromium and zinc rich wastewater

Dhir

Sharmila

Saradhi

2008

Braz. J. Plant Physiol.

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Investigations were carried out to evaluate alterations in photosynthetic performance of Salvinia natans (L.) exposed to chromium (Cr) and zinc (Zn) rich wastewater. Accumulation of high levels of Cr and Zn in plants affected photosynthetic electron transport. Photosystem-(PS) II-mediated electron transport was enhanced in plants exposed to Cr rich wastewater while a decline was observed in Zn-exposed plants. Photosystem-I-mediated electron transport increased in plants exposed to Cr and Zn rich wastewater. Efficiency of photosystem II (F v /F m ) measured by fluorescence did not show any significant change in Cr-exposed plants but a decrease was observed in Zn-exposed plants as compared to the control. The enhancement in PS I-induced cyclic electron transport in Cr and Zn exposed plants led to a build up of the transthylakoidal proton gradient (∆pH) which subsequently helped in maintaining the photophosphorylation potential to meet the additional requirement of ATP under stress. The carbon assimilation potential was adversely affected as evident from the decrease in Rubisco (EC 4.1.1.39) activity. The alterations in photosynthetic electron transport affected stromal redox status and induced variations in the level of stromal components such as pyridine nucleotides in plants exposed to Cr and Zn rich wastewater. The present investigations revealed that alteration in the photosynthetic efficiency of Salvinia exposed to Cr could primarily be the result of a decline in carbon assimilation efficiency relative to light-mediated photosynthetic electron transport, though in the case of Zn-exposed plants both these factors were affected equally. Key words: carbon assimilation, electron transport, heavy metals, photophosphorylation, redox status Desempenho fotossintético de plantas de Salvinia natans expostas a água de esgoto rica em cromo e zinco: Avaliou-se o desempenho fotossintético de plantas de Salvinia natans L. expostas a água de esgoto rica em cromo (Cr) e zinco (Zn). O acúmulo de Cr e Zn em altos níveis afetou o transporte fotossintético de elétrons. O transporte de elétrons mediado pelo fotossistema (FS) II aumentou nas plantas expostas ao esgoto rico em Cr, observando-se o oposto nas plantas expostas ao esgoto rico em Zn. O transporte de elétrons mediado pelo FS I aumentou nas plantas expostas ao esgoto rico tanto em Cr como em Zn. A eficiência do FS II (F v /F m ) avaliada por fluorescência não variou significativamente em resposta ao Cr, porém reduziu-se nas plantas expostas ao esgoto rico em Zn, em comparação com as plantas-controle. O aumento do transporte cíclico de elétrons associado ao FS I acarretou em aumento do gradiente transtilacoidal de prótons (∆pH) que, por seu turno, esteve associado com o potencial de fotofosforilação para suportar as necessidades adicionais de ATP sob condições de estresse. O potencial de assimilação do carbono foi decrescido, conforme se deduz da menor atividade da Rubisco (EC 4.1.1.39). As alterações no transporte fotossintético de elétrons afetaram o status redox do estro...

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NADP-malate Dehydrogenase Activity during Photosynthesis in Illuminated Spinach Chloroplasts

Cited by 24 publications

References 18 publications

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Evidence That Isoprene Emission Is Not Limited by Cytosolic Metabolites. Exogenous Malate Does Not Invert the Reverse Sensitivity of Isoprene Emission to High [CO₂]

Photosynthetic performance of Salvinia natans exposed to chromium and zinc rich wastewater

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NADP-malate Dehydrogenase Activity during Photosynthesis in Illuminated Spinach Chloroplasts

Cited by 24 publications

References 18 publications

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Evidence That Isoprene Emission Is Not Limited by Cytosolic Metabolites. Exogenous Malate Does Not Invert the Reverse Sensitivity of Isoprene Emission to High [CO2]

Photosynthetic performance of Salvinia natans exposed to chromium and zinc rich wastewater

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Evidence That Isoprene Emission Is Not Limited by Cytosolic Metabolites. Exogenous Malate Does Not Invert the Reverse Sensitivity of Isoprene Emission to High [CO₂]