Related Experiment Video
Updated: Aug 19, 2026

Measuring Spatial and Temporal Ca2+ Signals in Arabidopsis Plants
Published on: September 2, 2014
Ca2+ influx into lily pollen grains through a hyperpolarization-activated Ca2+-permeable channel which can be
Zhong-lin Shang1, Li-geng Ma, Hai-lin Zhang
1Institute of Molecular and Cell Biology, Hebei Normal University, Shijiazhuang 050016, PR China.
Abstract:
Confocal laser scanning microscopy (CLSM) and whole-cell patch-clamp were used to investigate the role of Ca2+ influx in maintaining the cytosolic Ca2+ concentration ([Ca2+]c) and the features of the Ca2+ influx pathway in germinating pollen grains of Lilium davidii D. [Ca2+]c decreased when Ca2+ influx was inhibited by EGTA or Ca2+ channel blockers. A hyperpolarization-activated Ca2+-permeable channel, which can be suppressed by trivalent cations, verapamil, nifedipine or diltiazem, was identified on the plasma membrane of pollen protoplasts with whole-cell patch-clamp recording. Calmodulin (CaM) antiserum and W7-agarose, both of which are cell-impermeable CaM antagonists, lead to a [Ca2+]c decrease, while exogenous purified CaM triggers a transient increase of [Ca2+]c and also remarkably activated the hyperpolarization-activated Ca2+ conductance on plasma membrane of pollen protoplasts in a dose-dependent manner. Both the increase of [Ca2+]c and the activation of Ca2+ conductance which were induced by exogenous CaM were inhibited by EGTA or Ca2+ channel blockers. This primary evidence showed the presence of a voltage-dependent Ca2+-permeable channel, whose activity may be regulated by extracellular CaM, in pollen cells.
Related Concept Videos
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
G-Protein Gated Ion Channels
Sensory organs,...
Amplifying Signals via Second Messengers
Intracellular Signaling Cascades

