scholarly journals Morphology made for movement: formation of diverse stomatal guard cells

2021 ◽  
Vol 63 ◽  
pp. 102090
Author(s):  
Roxane P. Spiegelhalder ◽  
Michael T. Raissig
1996 ◽  
Vol 134 (3) ◽  
pp. 463-469 ◽  
Author(s):  
D. L. R. SILVA ◽  
SARAH J. HONOUR ◽  
T. A. MANSFIELD

2015 ◽  
Vol 25 (7) ◽  
pp. 928-935 ◽  
Author(s):  
Christof Lind ◽  
Ingo Dreyer ◽  
Enrique J. López-Sanjurjo ◽  
Katharina von Meyer ◽  
Kimitsune Ishizaki ◽  
...  

2001 ◽  
Vol 44 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Maria das Graças Sajo ◽  
Silvia Rodrigues Machado

The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells.


2011 ◽  
Vol 52 (7) ◽  
pp. 1238-1248 ◽  
Author(s):  
Maki Hayashi ◽  
Shin-ichiro Inoue ◽  
Koji Takahashi ◽  
Toshinori Kinoshita

2013 ◽  
Vol 64 (12) ◽  
pp. 3551-3566 ◽  
Author(s):  
Sasan Aliniaeifard ◽  
Uulke van Meeteren

1992 ◽  
Vol 99 (4) ◽  
pp. 615-644 ◽  
Author(s):  
M R Blatt

Intracellular microelectrode recordings and a two-electrode voltage clamp have been used to characterize the current carried by inward rectifying K+ channels of stomatal guard cells from the broadbean, Vicia faba L. Superficially, the current displayed many features common to inward rectifiers of neuromuscular and egg cell membranes. In millimolar external K+ concentrations (Ko+), it activated on hyperpolarization with half-times of 100-200 ms, showed no evidence of time- or voltage-dependent inactivation, and deactivated rapidly (tau approximately 10 ms) on clamping to 0 mV. Steady-state conductance-voltage characteristics indicated an apparent gating charge of 1.3-1.6. Current reversal showed a Nernstian dependence on Ko+ over the range 3-30 mM, and the inward rectifier was found to be highly selective for K+ over other monovalent cations (K+ greater than Rb+ greater than Cs+ much greater than Na+). Unlike the inward rectifiers of animal membranes, the current was blocked by charybdotoxin and alpha-dendrotoxin (Kd much less than 50 nM), as well as by tetraethylammonium chloride (K1/2 = 9.1 mM); gating of the guard cell K+ current was fixed to voltages near -120 mV, independent of Ko+, and the current activated only with supramillimolar K+ outside (EK+ greater than -120 mV). Most striking, however, was inward rectifier sensitivity to [H+] with the K+ current activated reversibly by mild acid external pH. Current through the K+ inward rectifier was found to be largely independent of intracellular pH and the current reversal (equilibrium) potential was unaffected by pHo from 7.4 to 5.5. By contrast, current through the K+ outward rectifier previously characterized in these cells (1988. J. Membr. Biol. 102:235) was largely insensitive to pHo, but was blocked reversibly by acid-going intracellular pH. The action of pHo on the K+ inward rectifier could not be mimicked by extracellular Ca2+ for which changes in activation, deactivation, and conductance were consonant with an effect on surface charge ([Ca2+] less than or equal to 1 mM). Rather, extracellular pH affected activation and deactivation kinetics disproportionately, with acid-going pHo raising the K+ conductance and shifting the conductance-voltage profile positive-going along the voltage axis and into the physiological voltage range. Voltage and pH dependencies for gating were consistent with a single, titratable group (pKa approximately 7 at -200 mV) residing deep within the membrane electric field and accessible from the outside.(ABSTRACT TRUNCATED AT 400 WORDS)


Sign in / Sign up

Export Citation Format

Share Document