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Plant Physiol. 1987 Jun;84(2):374-80. doi: 10.1104/pp.84.2.374.

Polyamine uptake in carrot cell cultures.

Plant physiology

R Pistocchi, N Bagni, J A Creus

Affiliations

  1. Institute of Botany, University of Bologna, Bologna, Italy.

PMID: 16665446 PMCID: PMC1056586 DOI: 10.1104/pp.84.2.374

Abstract

Putrescine and spermidine uptake into carrot (Daucus carota L.) cells in culture was studied. The time course of uptake showed that the two polyamines were very quickly transported into the cells, reaching a maximum absorption within 1 minute. Increasing external polyamine concentrations up to 100 millimolar showed the existence of a biphasic system with different affinities at low and high polyamine concentrations. The cellular localization of absorbed polyamines was such that a greater amount of putrescine was present in the cytoplasmic soluble fraction, while spermidine was mostly present in cell walls. The absorbed polyamines were released into the medium in the presence of increasing external concentrations of the corresponding polyamine or Ca(2+). The effects of Ca(2+) were different for putrescine and spermidine; putrescine uptake was slightly stimulated by 10 micromolar Ca(2+) and inhibited by higher concentrations, while for spermidine uptake there was an increasing stimulation in the Ca(2+) concentration range between 10 micromolar and 1 millimolar. La(3+) nullified the stimulatory effect of 10 micromolar Ca(2+) on putrescine uptake and that of 1 millimolar Ca(2+) on spermidine uptake. La(3+) at 0.5 to 1 millimolar markedly inhibited the uptake of both polyamines, suggesting that it interferes with the sites of polyamine uptake. Putrescine uptake was affected to a lesser extent by metabolic inhibitors than was spermidine uptake. It is proposed that the entry of polyamines into the cells is driven by the transmembrane electrical gradient, with a possible antiport mechanism between external and internal polyamine molecule.

References

  1. J Gen Microbiol. 1982 Mar;128(3):557-63 - PubMed
  2. Exp Cell Res. 1968 Apr;50(1):151-8 - PubMed
  3. J Bacteriol. 1986 Mar;165(3):972-7 - PubMed
  4. Plant Physiol. 1981 Feb;67(2):373-8 - PubMed
  5. Plant Physiol. 1986 Feb;80(2):556-60 - PubMed
  6. Plant Physiol. 1985 Feb;77(2):398-402 - PubMed
  7. Proc Natl Acad Sci U S A. 1979 Jul;76(7):3184-8 - PubMed
  8. J Biol Chem. 1966 Aug 25;241(16):3714-23 - PubMed
  9. Plant Physiol. 1975 Mar;55(3):542-6 - PubMed
  10. Plant Physiol. 1983 Jan;71(1):1-6 - PubMed
  11. Biochim Biophys Acta. 1985 Jan 25;812(2):345-52 - PubMed
  12. Plant Physiol. 1984 Oct;76(2):490-7 - PubMed

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