Ca2+-sensitive and Ca2+-insensitive exocytosis in maize coleoptile protoplasts

G Thiel, J U Sutter, U Homann

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Ca2+ and osmotic driven extension of the surface area of maize coleoptile protoplasts was investigated using capacitance measurements and photolysis of the caged compound DM-nitrophen. Protoplasts responded to an elevation of cytoplasmic Ca2+ (Ca(i)) with a rapid burst in capacitance reaching a maximal increase of 1.3+/-1.1% over the resting cell capacitance. Subsequent lowering of the osmotic potential in the external medium by 210 mosmol caused a further increase in Cm by 26+/-6%. These data indicate two independent pathways for insertion of membrane into the plasma membrane. One is driven by Ca(i) and recruits membrane from a small pool. The osmotic evoked rise in surface area draws membrane from a much larger reservoir and may be driven by membrane tension.
LanguageEnglish
PagesR152-3
JournalPflugers Archiv - European Journal of Physiology
Volume439
Issue number3 Suppl
DOIs
Publication statusPublished - 2000

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Cotyledon
Protoplasts
Exocytosis
Zea mays
Membranes
Capacitance
Capacitance measurement
Photolysis
Cell membranes
Cell Membrane

Keywords

  • cell capacitance
  • maize coleoptile protoplasts
  • capacitance measurements
  • membrane

Cite this

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title = "Ca2+-sensitive and Ca2+-insensitive exocytosis in maize coleoptile protoplasts",
abstract = "Ca2+ and osmotic driven extension of the surface area of maize coleoptile protoplasts was investigated using capacitance measurements and photolysis of the caged compound DM-nitrophen. Protoplasts responded to an elevation of cytoplasmic Ca2+ (Ca(i)) with a rapid burst in capacitance reaching a maximal increase of 1.3+/-1.1{\%} over the resting cell capacitance. Subsequent lowering of the osmotic potential in the external medium by 210 mosmol caused a further increase in Cm by 26+/-6{\%}. These data indicate two independent pathways for insertion of membrane into the plasma membrane. One is driven by Ca(i) and recruits membrane from a small pool. The osmotic evoked rise in surface area draws membrane from a much larger reservoir and may be driven by membrane tension.",
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Ca2+-sensitive and Ca2+-insensitive exocytosis in maize coleoptile protoplasts. / Thiel, G; Sutter, J U; Homann, U.

In: Pflugers Archiv - European Journal of Physiology, Vol. 439, No. 3 Suppl, 2000, p. R152-3.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ca2+-sensitive and Ca2+-insensitive exocytosis in maize coleoptile protoplasts

AU - Thiel, G

AU - Sutter, J U

AU - Homann, U

PY - 2000

Y1 - 2000

N2 - Ca2+ and osmotic driven extension of the surface area of maize coleoptile protoplasts was investigated using capacitance measurements and photolysis of the caged compound DM-nitrophen. Protoplasts responded to an elevation of cytoplasmic Ca2+ (Ca(i)) with a rapid burst in capacitance reaching a maximal increase of 1.3+/-1.1% over the resting cell capacitance. Subsequent lowering of the osmotic potential in the external medium by 210 mosmol caused a further increase in Cm by 26+/-6%. These data indicate two independent pathways for insertion of membrane into the plasma membrane. One is driven by Ca(i) and recruits membrane from a small pool. The osmotic evoked rise in surface area draws membrane from a much larger reservoir and may be driven by membrane tension.

AB - Ca2+ and osmotic driven extension of the surface area of maize coleoptile protoplasts was investigated using capacitance measurements and photolysis of the caged compound DM-nitrophen. Protoplasts responded to an elevation of cytoplasmic Ca2+ (Ca(i)) with a rapid burst in capacitance reaching a maximal increase of 1.3+/-1.1% over the resting cell capacitance. Subsequent lowering of the osmotic potential in the external medium by 210 mosmol caused a further increase in Cm by 26+/-6%. These data indicate two independent pathways for insertion of membrane into the plasma membrane. One is driven by Ca(i) and recruits membrane from a small pool. The osmotic evoked rise in surface area draws membrane from a much larger reservoir and may be driven by membrane tension.

KW - cell capacitance

KW - maize coleoptile protoplasts

KW - capacitance measurements

KW - membrane

U2 - 10.1007/s004240000127

DO - 10.1007/s004240000127

M3 - Article

VL - 439

SP - R152-3

JO - Pflügers Archiv European Journal of Physiology

T2 - Pflügers Archiv European Journal of Physiology

JF - Pflügers Archiv European Journal of Physiology

SN - 0031-6768

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