The Effect of Heavy Metal Compounds on the Permeability of Chlorella Cells

Filippis, L.F. De

doi:10.1016/s0044-328x(79)80151-8

Cited by 81 publications

(24 citation statements)

References 16 publications

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“…Membrane damage measured as an increased K + efflux or electrolyte leakages from Cd-treated tissues was reported by many authors (De Fillipis, 1979;Fuhrer, 1982;Keck, 1978;Llamas et al, 2000). Cd 2+ significantly reduced the "normal" H + /K + exchange and the activity of plasma membrane ATPase (Obata et al, 1996), and strongly affected the activity of several enzymes (Siedlecka et al, 1997;Van Assche & Clijsters, 1990).…”

Section: Introductionmentioning

confidence: 71%

Short-and long-term effects of cadmium on transmembrane electric potential (E m) in maize roots

et al. 2006

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In this study, the effects of Cd on root growth, respiration, and transmembrane electric potential (Em) of the outer cortical cells in maize roots treated with various Cd concentrations (from 1 µM to 1 mM) for several hours to one week were studied. The Em values of root cells ranged between −120 and −140 mV and after addition of Cd they were depolarized immediately. The depolarization was concentration-dependent reaching the value of diffusion potential (ED) when the Cd concentration exceeded 100 µM. The values of ED ranged between −65 to −68 mV (−66 ± 1.42 mV). The maximum depolarization of Em was registered approx. 2.5 h after addition of Cd to the perfusion solution and in some cases, partial (Cd > 100 µM) or complete repolarization (Cd < 100 µM) was observed within 8-10 h of Cd treatment. In the time-dependent experiments (0 to 168 h) shortly after the maximum repolarization of Em a continuous concentrationdependent decrease of Em followed at all Cd concentrations. Depolarization of Em was accompanied by both increased electrolyte leakage and inhibition of respiration, especially in the range of 50 µM to 1 mM Cd, with the exception of root cells treated with 1 and 10 µM Cd for 24 and 48 h. Time course analysis of Cd impact on root respiration revealed that at higher Cd concentrations (> 50 µM) the respiration gradually declined (∼ 6 h) and then remained at this lowest level for up to 24 h. All the Cd concentrations used in this experiment induced significant inhibition of root elongation and concentrations higher than 100 µM stopped the root growth within the first day of Cd treatment. Our results suggest that Cd does not cause irreversible changes in the electrogenic plasma membrane H + ATPase because fusicoccin, an H + ATPase activator diminished the depolarizing effect of Cd on the Em. The depolarization of Em in the outer cortical cells of maize roots was the result of a cumulative effect of Cd on ATP supply, plasmalemma permeability, and activity of H + ATPase.

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Section: Introductionmentioning

confidence: 71%

Short-and long-term effects of cadmium on transmembrane electric potential (E m) in maize roots

et al. 2006

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“…Decreased binding of complexed Pb to cell wails and membranes presumably also decreases Pb toxicity, which is mainly caused by binding of Pb ions to cell walls. Binding of Pb to cell walls or plasma membranes reduce cell wail extension (Lane et al, 1978) or changes membrane permeability (De Filippis, 1979) and membrane potential (Aidid and Okamoto, 1992). The decreased binding may therefore explain why despite the high Pb content of the cortex cell wails (Table 1, Fig.2), root growth of the plants mycorrhizal withL, laccata was not affected.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of lead accumulation in mycorrhizal and non-mycorrhizal Norway spruce (Picea abies (L.) Karst.)

1996

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Twelve-week-old seedlings of Norway spruce (Picea abies (L.) Karst), non-mycorrhizal or mycorrhizal with Laccaria laccata, Paxillus involutus or Pisolithus tinctorius were exposed to 5 #M Pb for either 32 or 42 days in a quartz sand-nutrient solution system. Ultrathin sections of mycorrhizal and non-mycorrhizal short roots were examined by X-ray microanalysis. After 42 days Pb treatment, the Pb content of the cortex cell walls was lower in the non-mycorrhizal short roots and in the P. involutus mycorrhizae than in the mycorrhizae of L. laccata or P. tinctorius. The Pb content of the cell walls of the hyphal mantle was higher in P. involutus than in L. laccata or P. tinctorius. The short term experiment over 32 days showed that the Pb content of the cortex cell walls strongly increased during the first 16 days in the non-mycorrhizal roots and the L. laccata mycorrhizae, whereas it increased more slowly in the P. involutus mycorrhizae. After 32 days Pb treatment, the Pb content in the cortex cell walls in the P. involutus mycorrhizae was similar to that in the non-mycorrhizal roots. P. involutus also decreased Pb translocation from the roots to the stems. Mycorrhizal infection was not affected by Pb but with P. involutus, the amount of extramatrical mycelium was reduced by 50% on day 32 compared to day 16. The extramatrical mycelium of L. laccata was not reduced by Pb. It is concluded that ectomycorrhizal fungi differ in their effect on Pb accumulation in the roots of Norway spruce. The binding capacity of the extramatrical mycelium seems to be an important factor.

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“…In cells of the green alga Chlorella, the ability of the metals Zn, Hg, and Cu to induce potassium leakage was strongly correlated to the strength of the metal-sulphydryl bond (De Filippis, 1979). In higher plants, ATP-ases of the plasmalemma, responsible for electrogenic pumping and involved in the cellular permeability barrier, may be primarily affected by metals, since they are very sensitive to various sulphydryl reagents, including metals (Beffagna et al, 1979;Kennedy and Gonsalves, 1989).…”

Section: Introductionmentioning

confidence: 99%