Abstract
Cytoplasmic free calcium concentration([Ca2+]c) in pollen cells of Lilium daviddi is measured with confocal laser scanning microscopy to investigate the effect of heterotrimeric G protein (G protein) on [Ca2+]c and the possible signal transduction pathway of G protein triggering cellular calcium signal. After application, cholera toxin (CTX), an agonist of G protein, triggers a transient increase of [Ca2+]c in pollen cells, and evokes a spatial-temporal characteristic calcium dynamics; while pertussis toxin (PTX), a G protein antagonist, leads to the decrease of [Ca2+]c. Both L-type Ca2+ channel blocker verapamil and inhibitor of IP3 receptor heparin inhibit CTX-induced [Ca2+]c increase. The results show that G protein may play a role in the modulation of [Ca2+]c through enhancing the extracellular Ca2+ influx and releasing of Ca2+ from intracellular stores.
Supported by the National Natural Science Foundation of China(Grant No. 39930230). the Major State Basic Research Development Program of China (G1999011700) and the National Fund for Distinguished Young Scholars (No. 30025024)
Supported by the National Natural Science Foundation of China(Grant No. 39930230). the Major State Basic Research Development Program of China (G1999011700) and the National Fund for Distinguished Young Scholars (No. 30025024)
Notes
Supported by the National Natural Science Foundation of China(Grant No. 39930230). the Major State Basic Research Development Program of China (G1999011700) and the National Fund for Distinguished Young Scholars (No. 30025024)