Avtor/Urednik		Thiel, G; Rupnik, M; Zorec, R
Naslov		Raising the cytosolic Ca2+ concentration increases the membrane capacitance of maize coleoptile protoplasts: evidence for Ca2+-stimulated exocytosis
Tip		članek
Vir		Planta
Vol. in št.		Letnik 195, št. 2
Leto izdaje		1994
Obseg		str. 305-8
Jezik		eng
Abstrakt		Enhanced elongation of coleoptile cells has been proposed to be related to a rise in secretory activity. Therefore, to obtain a direct measurement of exocytotic events in maize (Zea mays L.) coleoptile protoplasts we used the patch-clamp method to record changes in membrane capacitance (Cm) as a parameter proportional to fluctuations of the membrane surface area. The secretory activity of protoplasts was correlated with the cytosolic free Ca2+ concentration (Ca2+)cyt): dialyzing protoplasts with 1 microM (Ca2+)cyt, caused a steady rise in Cm of 3.3qpF.s-1. In contrast, dialysis with a solution containing less th. 20 nM Ca2+ produced a small and persistent decrease in Cm. This demonstrates that secretory activity in coleoptile cells can be controlled by factors which modulate (Ca2+)cyt.
Deskriptorji		CORN PROTOPLASTS CELL MEMBRANE EXOCYTOSIS CALCIUM CYTOSOL CALCIUM CHANNELS