Fusion and fission of plasma-membrane material accommodates for osmotically induced changes in the surface area of guard-cell protoplasts

Planta ◽  
1998 ◽  
Vol 206 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Ulrike Homann
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Guard Cell ◽  
Membrane Material ◽  
Guard Cell Protoplasts ◽  
Induced Changes

Osmotically evoked shrinking of guard-cell protoplasts causes vesicular retrieval of plasma membrane into the cytoplasm

Planta ◽  
2000 ◽  
Vol 210 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Ulrich Kubitscheck ◽  
Ulrike Homann ◽  
Gerhard Thiel
Keyword(s):  
Plasma Membrane ◽  
Guard Cell ◽  
Guard Cell Protoplasts

scholarly journals External pH effects on the depolarization-activated K channels in guard cell protoplasts of Vicia faba.

1994 ◽  
Vol 103 (5) ◽  
pp. 807-831 ◽  
Author(s):  
N Ilan ◽  
A Schwartz ◽  
N Moran
Keyword(s):  
Plasma Membrane ◽  
Surface Charge ◽  
Vicia Faba ◽  
Guard Cell ◽  
Voltage Dependence ◽  
Single Channel ◽  
Ph Effects ◽  
Homogeneous Surface ◽  
K Channels ◽  
Guard Cell Protoplasts

Previous studies reveal that the pH of the apoplastic solution in the guard cell walls may vary between 7.2 and 5.1 in closed and open stomata, respectively. During these aperture and pH changes, massive K+ fluxes cross the cellular plasma membrane driving the osmotic turgor and volume changes of guard cells. Therefore, we examined the effect of extracellular pH on the depolarization-activated K channels (KD channels), which constitute the K+ efflux pathway, in the plasma membrane of Vicia faba guard cell protoplasts. We used patch clamp, both in whole cells as well as in excised outside-out membrane patches. Approximately 500 KD channels, at least, could be activated by depolarization in one protoplast (density: approximately 0.6 micron-2). Acidification from ph 8.1 to 4.4 decreased markedly the whole-cell conductance, GK, of the KD channels, shifted its voltage dependence, GK-EM, to the right on the voltage axis, slowed the rate of activation and increased the rate of deactivation, whereas the single channel conductance was not affected significantly. Based on the GK-EM shifts, the estimated average negative surface charge spacing near the KD channel is 39 A. To quantify the effects of protons on the rates of transitions between the hypothesized conformational states of the channels, we fitted the experimental macroscopic steady state conductance-voltage relationship and the voltage dependence of time constants of activation and deactivation, simultaneously, with a sequential three-state model CCO. In terms of this model, protonation affects the voltage-dependent properties via a decrease in localized, rather than homogeneous, surface charge sensed by the gating moieties. In terms of either the CO or CCO model, the protonation of a site with a pKa of 4.8 decreases the voltage-independent number of channels, N, that are available for activation by depolarization.

scholarly journals Biochemical Characterization of Plasma Membrane H+-ATPase Activation in Guard Cell Protoplasts of Arabidopsis thaliana in Response to Blue Light

2005 ◽  
Vol 46 (6) ◽  
pp. 955-963 ◽  
Author(s):  
Kumi Ueno ◽  
Toshinori Kinoshita ◽  
Shin-ichiro Inoue ◽  
Takashi Emi ◽  
Ken-ichiro Shimazaki
Keyword(s):  
Arabidopsis Thaliana ◽  
Plasma Membrane ◽  
Blue Light ◽  
Guard Cell ◽  
Biochemical Characterization ◽  
Guard Cell Protoplasts

scholarly journals Lysosome exocytosis is required for mitosis

2018 ◽  
Author(s):  
Charlotte Nugues ◽  
Nordine Helassa ◽  
Dayani Rajamanoharan ◽  
Robert D Burgoyne ◽  
Lee P Haynes
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Membrane Trafficking ◽  
Regulatory Mechanism ◽  
Significant Proportion ◽  
Genetic Material ◽  
Adherent Cells ◽  
Membrane Material ◽  
Daughter Cells ◽  
Phosphatidylinositol 4

AbstractMitosis, the accurate segregation of duplicated genetic material into what will become two new daughter cells, is accompanied by extensive membrane remodelling and membrane trafficking activities. Early in mitosis, adherent cells partially detach from the substratum, round up and their surface area decreases. This likely results from an endocytic uptake of plasma membrane material. As cells enter cytokinesis they re-adhere, flatten and exhibit an associated increase in surface area. The identity of the membrane donor for this phase of mitosis remains unclear. Here we show by biochemical and imaging approaches that lysosomes undergo exocytosis at telophase and that this requires the activity of phosphatidylinositol 4-kinase-IIIβ. Inhibition of lysosome exocytosis resulted in mitotic failure in a significant proportion of cells suggesting that this facet of lysosome physiology is essential and represents a new regulatory mechanism in mitosis.

scholarly journals Inhibition of Blue Light-Dependent H+ Pumping by Abscisic Acid through Hydrogen Peroxide-Induced Dephosphorylation of the Plasma Membrane H+-ATPase in Guard Cell Protoplasts

2004 ◽  
Vol 136 (4) ◽  
pp. 4150-4158 ◽  
Author(s):  
Xiao Zhang ◽  
Hengbin Wang ◽  
Atsushi Takemiya ◽  
Chun-peng Song ◽  
Toshinori Kinoshita ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Plasma Membrane ◽  
Abscisic Acid ◽  
Blue Light ◽  
Guard Cell ◽  
Guard Cell Protoplasts

Osmocytosis and Vacuolar Fragmentation in Guard Cell Protoplasts: Their Relevance to Osmotically-lnduced Volume Changes in Guard Cells

1993 ◽  
Vol 44 (10) ◽  
pp. 1569-1577 ◽  
Author(s):  
WILFRIED DIEKMANN ◽  
RAINER HEDRICH ◽  
KLAUS RASCHKE ◽  
DAVID G. ROBINSON
Keyword(s):  
Guard Cell ◽  
Guard Cells ◽  
Volume Changes ◽  
Guard Cell Protoplasts
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