Effect of Monochromatic Light on Proton Efflux of the Blue-Green Alga <i>Anabaena variabilis</i>

Scherer, Stephen W.; Hinrichs, I.; Böger, Peter

doi:10.1104/pp.81.3.939

Cited by 6 publications

(6 citation statements)

References 14 publications

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“…The uncoupler carbonylcyanide-m-chlorophenylhydrazone, the ATPase inhibitor N,N-dichlorohexylcarbodiimide, the energy transfer inhibitors nitrofen (23) and venturicidin, and the inhibitor ofphotosynthetic electron transport, DCMU, each severely inhibited the acidification. This might indicate that in Synechococcus the acidification depends on the activity of an ATPase (22,23), or the pool size of ATP. Since the observed Na+-dependent acidification could also stem from the activity of an Na+/H+ antiporter ( (at different concentrations), in a wide variety of eukaryotic systems (10).…”

Section: And Discussionmentioning

confidence: 99%

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Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria

Scherer¹,

Lerner²

1989

Plant Physiol.

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We investigated the nature of the light-induced, sodium-dependent acidification of the medium and the uptake of sodium by Synechococcus. The rate of acidification (net H+ efflux) was strongly and specifically stimulated by sodium. The rates of acidification and sodium uptake were strongly affected by the pH of the medium; the optimal pH for both processes being in the alkaline pH range. Net proton efflux was severely inhibited by inhibitors of adenosine triphosphatase activity, energy transfer, and photosynthetic electron transport, but was not affected by the presence of inorganic carbon (C,). Ught and C, stimulated the uptake of sodium, but the stimulation by C, was observed only when C, was present at the time sodium was provided. Amiloride, a potent inhibitor of Na /H+ antiport and Na+ channels, stimulated the rate of acidification but inhibited the rate of sodium uptake. It is suggested that acidifiation might stem from the activity of a light dependent proton excreting adenosine triphosphatase, while sodium transport seems to be mediated by both Na+/H+ antiport and Na uniport.Cyanobacteria possess a mechanism for concentrating CO2 at the carboxylating site (1-3, 7, 8, 13, 27). The interconversion between different inorganic carbon (C12) species during uptake and accumulation of Ci (26,28) that the acidification was due to the activity of a Na+/H+ antiporter. A third alternative that should perhaps be considered is a PM located proton pump (1 1) the activity of which is light and sodium dependent.Sodium ions play a major role in cyanobacterial photosynthesis, particularly in the uptake of Ci (6,9,14,21 2Abbreviations: Ci, inorganic carbon; PM, plasma membrane. different models were postulated (9, 21) to explain the role of Nae in C~uptake:1. A Na+/H+ antiporter (4) operates to regulate and maintain the intracellular pH during Cj uptake.2. Na+/HCO3_ symport secondary to a primary Na+ pump operates to accumulate Ci at the expense of the 4INa+.3. Na+ binds to the C1 carrier and alters its kinetic parameters.The third alternative might be distinguished from 1 and 2 since Na+ transport is not envisaged as a compulsory requirement, as in the case of models 1 and 2. It is difficult, however, to distinguish between models 1 and 2 since both would require large, Cs-dependent Na+ fluxes into a small compartment. This flux of Na+ should have the same magnitude regardless of which model is correct. Obviously, one does not expect to measure a sustained net Na+ uptake on the supply of Ci (14), particularly in the case of model 2 since this would dissipate the 4$Na+, the driving force for the accumulation of Ci in the case of model 2.In the experiments reported here we determined the uptake of 22Na+ and H+ efflux by the mutant E1, isolated from Synechococcus PCC 7942 (12). This mutant is capable of accumulating Cj like the wild type but is defective in its ability to utilize the intracellular CQ pool for photosynthesis and hence it requires high CO2 for growth. Thus, possible complications due to the photosyntheti...

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Section: And Discussionmentioning

confidence: 99%

“…Scherer et al (22)(23)(24)(25) demonstrated a fast phase of Na+ dependent acidification of the medium, when dark adapted cells ofAnabaena were illuminated. They attributed this phase to the interconversion between CO2 and HCO3-during uptake of Ci (25).…”

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confidence: 99%

Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria

Scherer¹,

Lerner²

1989

Plant Physiol.

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“…H + -extrusion was suggested to depend on a K + -stimulated vanadate sensitive envelope P-type H + -ATPase ( Scherer et al, 1986 ; Berkowitz and Peters, 1993 ; Mi et al, 1994 ; Shingles and McCarty, 1994 ) but the Arabidopsis genome does not encode for chloroplast predicted P-type H + -pumps ( Axelsen and Palmgren, 2001 ). Other reports found that the envelope ATPase activity is sensitive to oligomycin, which is not a P-type ATPase inhibitor but a F o subunit inhibitor of the F 1 F o ATP Synthase.…”

Section: The H + -Gradient Across the Chloroplast mentioning

confidence: 99%

Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast

et al. 2016

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Proton gradients are fundamental to chloroplast function. Across thylakoid membranes, the light induced -proton gradient is essential for ATP synthesis. As a result of proton pumping into the thylakoid lumen, an alkaline stromal pH develops, which is required for full activation of pH-dependent Calvin Benson cycle enzymes. This implies that a pH gradient between the cytosol (pH 7) and the stroma (pH 8) is established upon illumination. To maintain this pH gradient chloroplasts actively extrude protons. More than 30 years ago it was already established that these proton fluxes are electrically counterbalanced by Mg2+, K+, or Cl- fluxes, but only recently the first transport systems that regulate the pH gradient were identified. Notably several (Na+,K+)/H+ antiporter systems where identified, that play a role in pH gradient regulation, ion homeostasis, osmoregulation, or coupling of secondary active transport. The established pH gradients are important to drive uptake of essential ions and solutes, but not many transporters involved have been identified to date. In this mini review we summarize the current status in the field and the open questions that need to be addressed in order to understand how pH gradients are maintained, how this is interconnected with other transport processes and what this means for chloroplast function.

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“…The periodicity of net H' excretion may have been caused by a variation of the activity of the primary proton pump, the PM H'-ATPase. There are several reports of stimulation or inhibition of ATPases by different light qualities (Felle and Bertl, 1986;Serrano et al, 1988;Scherer et al, 1986). Another possible primary H'-pumping system, a proton-pumping electron transport system in the PM, may also, alone or together with the H+-ATPase, change its activity (refs.…”

Section: Discussionmentioning

confidence: 99%

Light‐dependent Proton Excretion of Wheat (Triticum aestivum L.) and Maize (Zea mays L.) Roots

et al. 1995

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We investigated the change of root net woton excretion of seedlings of Triticum aestivum L. md Zea mays L. with daily variation of illumination ising a multi-channel pH-stat system. We found an in-:rease of net proton excretion during darkness and a lrop after the beginning of illumination. Inhibition of zarotenoid biosynthesis by norflurazone and photoxidation of chlorophylls did not change the periodicity 3r its induction. The induction of diurnal periodicity was possible with blue, green and red light. After induction the oscillation of net proton excretion continued for at least two cycles under constant light. We conclude that net H+ excretion of wheat and maize roots may be regulated by an endogenous clock or by a signal from the leaves. The nature of such a hypothetical signal remains unknown.

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Effect of Monochromatic Light on Proton Efflux of the Blue-Green Alga Anabaena variabilis

Cited by 6 publications

References 14 publications

Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria

Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria

Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast

Light‐dependent Proton Excretion of Wheat (Triticum aestivum L.) and Maize (Zea mays L.) Roots

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Effect of Monochromatic Light on Proton Efflux of the Blue-Green Alga Anabaena variabilis

Cited by 6 publications

References 14 publications

Nature of the Light-Induced H+ Efflux and Na+ Uptake in Cyanobacteria

Nature of the Light-Induced H+ Efflux and Na+ Uptake in Cyanobacteria

Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast

Light‐dependent Proton Excretion of Wheat (Triticum aestivum L.) and Maize (Zea mays L.) Roots

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Product

Resources

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Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria

Nature of the Light-Induced H⁺ Efflux and Na⁺ Uptake in Cyanobacteria