Salt accumulation and adenosine triphosphate in carrot xylem tissue.

Atkinson, M. R.; Eckermann, Gail; Grant, M.H.; Robertson, R. N.

doi:10.1073/pnas.55.3.560

Cited by 36 publications

(16 citation statements)

References 3 publications

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“…NADH-driven ion uptake in roots and protoplasts is commonly inhibited by the uncoupler (p-trifluoromethoxy)carbonyl cyanide phenylhydrazone (21). The question cannot be answered with any more assurance than previously (1,27,29), but there is now more reason to ask it.…”

Section: Resultsmentioning

confidence: 94%

Further Characterization on the Transport Property of Plasmalemma NADH Oxidation System in Isolated Corn Root Protoplasts

Lin¹

1984

Plant Physiol.

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Recent experiments show that exogenous NADH increases the 02 consumption and uptake of inorganic ions into isolated corn (Zea mays L. Pioneer Hybrid 3320) root protoplasts (Lin 1982, Proc Natl Acad Sci USA 79: 3773-3776). A mild treatment of protoplasts with trypsin released most of the NADH oxidation system from the plasmalemma (Lin 1982 Plant Physiol 70: 326-328). Further studies on this system showed that-exogenous NADH (1.5 millimolar) tripled the proton efflux from the protoplasts thus generating a greater electrochemical proton gradient across the plasmalemma. Trypsin also released ubiquinone (11.95 nanomoles per milligrams protein) but not flavin or cytochrome from the system. Kinetic analyses showed that 1.5 millimolar NADH quadrupled V.,,, of the mechanism I (saturable) component of K' uptake, while K,,, was not affected. Diethylstibestrol and vanadate inhibited basal (ATPase-mediated) K' influx and H' efflux, while NADH-stimulated K' uptake was not or only slightly inhibited. p-Chloromercuribenzenesulfonic acid, N,N'-dicyclohexylcarbodiimide, ethidium bromide, and oligomycin inhibited both ATPase-and NADH-mediated H' and K' fluxes. A combination of 10 millimolar fusicoccin and 1.5 millimolar NADH gave an 11-fold increase of K' influx and a more than 3-fold increase of H' efflux. It is concluded that a plasmalemma ATPase is not involved in the NADH-mediated ion transport mechanism. NADH oxidase is a -SH containing enzyme (protein) and the proton channel is an important element in this transport system. Fusicoccin synergistically stimulates the effect of NADH on K' uptake.Plasmalemma redox systems have been suggested in various eukaryotic cells (8,9,22,23,26 Determination of Cytochromes, Flavin, and Quinones. Previously reported methods were used to extract and measure the Cyt (5), flavin (13), and quinones (11,15) in the trypsin-released plasmalemma NADH redox system ofcorn root protoplasts (20).In brief, Cyt were extracted by adding 0.2 ml of 0.1 M A12 (SO4)3 into 2 ml of trypsin-treated protoplast supernatant (20) and adjusted with 3% A12(SO4)3 or 5 N NaOH to pH 4.5. The mixture was kept in an ice bucket and stirred for 2 h. It was then filtered through a No. 1 prewetted Whitman filter paper. The filtrate was adjusted to pH 8.2 to 8.4 with concentrated NH40H 2 Abbreviations: DCCD, N,N'-dicyclohexylcarbodiimide; DES: dieth-

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Section: Resultsmentioning

confidence: 94%

Further Characterization on the Transport Property of Plasmalemma NADH Oxidation System in Isolated Corn Root Protoplasts

Lin¹

1984

Plant Physiol.

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“…6), we conclude that much of the increase of ADP occurs in the cytoplasm. Increased cytoplasmic ADP could result from either direct utilization of ATP in salt accumulation as proposed by Sutcliffe and Hackett (17), or by slowing of oxidative phosphorylation when accumulation is coupled with charge separation, as proposed in the chemiosmotic hypothesis (4,12,14). Our experiments do not distinguish between these two alternative mechanisms.…”

Section: Resultsmentioning

confidence: 99%

“…A trace from the oxygen electrode before and after adding KCl (Fig. 2) shows that the increase in respiration is substantially completed within not more than 4 for a crossover at PGK between 2 and 2.5 min (Fig. 3), no other regulator reaction is stimulated while the respiratory flux is increasing.…”

Section: Resultsmentioning

confidence: 99%

Regulation of Salt Respiration in Carrot Root Slices

Adams¹,

Rowan

1972

Plant Physiol.

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In slices of carrot-phloem parenchyma washed for 7 days in water at 20 C, 50 mM KCI stimulates respiration by up to 100% of the ground respiration within 4 minutes of application. The The increase in rate of oxygen uptake usually occurring when washed slices of plant tissue are treated with salt solutions was described as "salt" respiration by Robertson (13). Although he initially believed that the extra respiration was essential for accumulation of salt, subsequently Robertson and Thorne (15) observed accumulation without salt respiration, and Atkinson and Polya (5) markedly inhibited respiration of carrot slices with ethionine without seriously inhibiting salt accumulation.In the experiments reported here, we measured the rate of oxygen uptake immediately after applying KCl to slices of carrot-phloem parenchyma and investigated the reactions regulating the rate of respiration while it was increasing.As in a previous paper (3), we identify the reactions of glycolysis concerned by applying the crossover theorem of Chance (7), as applied to the glycolytic sequence (10). A site of regulation is identified during a period of increasing influx of respiration as the irreversible reaction at which substrate is depleted and product increased during that period (3, 7 to be in quasi-equilibrium with TP3 (11) and the concentration of the latter used in detecting crossovers. ADP is a substrate for both PGK and PK and, although one of the two may be the regulator reaction, change in ADP must affect both; since the reactions of the glycolytic series between PGK and PK are reversible, accumulation of 3PGA when PGK is stimulated, or depletion of PEP when PK is stimulated, will tend to be reduced, thus masking crossovers which will then be shown only by depletion of substrate (PGK) or accumulation of product (PK). HK and PFK would be affected in the same way.The experiments reported here were carried out on slices from the same batches as those used in the previous reports on induced respiration (1, 2, 3). MATERIALS AND METHODSMethods used for preparing slices of carrot-phloem parenchyma, for measuring oxygen uptake, and concentrations of metabolites were as previously described (3). Slices were treated with KCl in the electrode flask either by adding concentrated KCl or by changing the liquid in the flask. Washed tissue (60 g) to be treated with KCl was placed in a bag of Fiberglas netting and held in distilled water to equilibrate for 30 min. Excess water was then removed by shaking, and the bag was transferred to 3 liters of 50 mm KCI for the required time, removed again, quickly shaken free of salt solution, and plunged into liquid N2 for 4 min. A series of extracts using HCIO, (3) was prepared from batches of treated, frozen tissue at 42, 73, and 166 hr (Fig. 1). Most extracts in each series were prepared within the 4 min period in which the respiratory flux changed, for only then does the crossover theorem apply (7,10). Extracts were also prepared from samples of tissue "treated" with distilled water for up to 5...

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“…We also made measurements of various properties that gave evidence of their normal biological activity. The loss of this activity, in our experience, was characterized by a final loss of turgor, browning of both tissue and washing solutions, and a failure to respond in respiration rate to both the addition of salts and 2,4-dinitrophenol.The inclusion of 50 /Lg/ml of chloramphenicol has been shown (Edelman and Hall 1965;Leaver and Edelman 1965;Atkinson et al 1966) to prevent the multiplication of bacteria in disks of storage tissue. Also Marinos (1962) and Jones and Lunt (1967) have shown that the maintenance of cell membrane structure requires a supply of calcium.…”

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confidence: 99%

“…The inclusion of 50 /Lg/ml of chloramphenicol has been shown (Edelman and Hall 1965;Leaver and Edelman 1965;Atkinson et al 1966) to prevent the multiplication of bacteria in disks of storage tissue. Also Marinos (1962) and Jones and Lunt (1967) have shown that the maintenance of cell membrane structure requires a supply of calcium.…”

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confidence: 99%

Maintenanance of Viability of Carrot Tissue Slices in Washing Solutions After Cutting

Wildes¹,

Neales²

1971

Aust. Jnl. Of Bio. Sci.

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In studies of the characteristics of the uptake of boric acid by plant tissues (Wildes and Neales, unpublished data) we used disks cut from carrot roots. Bacon, MacDonald, and Knight (1965) have emphasized the necessity of using storage tissue free of bacteria for such physiological studies. In the course of our experiments we therefore investigated the extent of bacterial contamination in carrot disks immediately after cutting, and also examined the effects of chloramphenicol and calcium chloride in the washing solution on the extent of the development of bacterial contamination in the disks. We also made measurements of various properties that gave evidence of their normal biological activity. The loss of this activity, in our experience, was characterized by a final loss of turgor, browning of both tissue and washing solutions, and a failure to respond in respiration rate to both the addition of salts and 2,4-dinitrophenol.The inclusion of 50 /Lg/ml of chloramphenicol has been shown (Edelman and Hall 1965;Leaver and Edelman 1965;Atkinson et al. 1966) to prevent the multiplication of bacteria in disks of storage tissue. Also Marinos (1962) and Jones and Lunt (1967) have shown that the maintenance of cell membrane structure requires a supply of calcium. In its absence there is a loss of cell contents (Skou 1963;Van Steveninck 1965a;Garrard and Humphreys 1967; van Goor 1968) and also an impairment in the ability of barley roots to absorb potassium (Epstein 1961). Therefore we investigated: (1) the extent of bacterial contamination with washing time; (2) the effellt of the inclusion of chloramphenicol in the washing solution and the effect of a spectrum of antibiotics on the growth of the contaminating bacteria; and (3) the effect of calcium chloride in the washing solution on the deterioration of carrot disks. MethodsCarrot disks were cut from the phloem tissue of intact roots, obtained periodically from the local market. The roots were thickly peeled and cut into slices 1 mm thick. Disks 10 mm in diameter were then cut from these slices with a sterilized cork-borer, and placed into 4 litres of washing solution maintained at room temperature (c. 18°C). This washing solution was changed several times in the first 3-4 hr, and then daily until the disks were used.

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Salt accumulation and adenosine triphosphate in carrot xylem tissue.

Cited by 36 publications

References 3 publications

Further Characterization on the Transport Property of Plasmalemma NADH Oxidation System in Isolated Corn Root Protoplasts

Further Characterization on the Transport Property of Plasmalemma NADH Oxidation System in Isolated Corn Root Protoplasts

Regulation of Salt Respiration in Carrot Root Slices

Maintenanance of Viability of Carrot Tissue Slices in Washing Solutions After Cutting

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