Possible Involvement of Mechanosensitive Ca2+ Channels of Plasma Membrane in Mechanoperception in Chara

Abstract

;When an internodal cell of Chara corallina was stimulated with a mechanical pulse of various amplitudes lasting for 0.1 s (mechanical stimulus), the cell generated a receptor potential, which was highly dependent not only on the strength of the stimulus but also on the extracellular Cl -concentration. Extracellular Ca 2+ was indispensable for generating receptor potential, since removal of Ca 2+ reversibly inhibited generation of the receptor potential. The cytoplasmic Ca 2+ level transiently rose upon mechanical stimulation. The stronger the mechanical stimulus, the larger was the increase in the cytoplasmic level of Ca 2+ . It is proposed that the first step of receptor potential is an activation of mechanosensitive Ca 2+ channels at the plasma membrane.

Mechano-sensitive orientation of cortical microtubules during gravitropism in azuki bean epicotyls

“…9b), suggesting involvement of SA channels in mechano-sensitive orientation of cMT. The plant plasma membrane seems to be equipped with various SA channels, Ca 2+ , K + and anion channels (Falke et al 1988;Cosgrove and Hedrich 1991;Ding and Pickard 1993;Pickard and Ding 1993;Shimmen 1997;Kaneko et al 2005). Among these ions, Ca 2+ seems to be the most plausible candidate involved in control of cMT, since this ion can work as a second messenger.…”

Plant Ion Channels: Gene Families, Physiology, and Functional Genomics Analyses

“…In plants the depolarizing phase of action potentials is, however, not mediated by Na + channels, owing to the lack of a suitable Na + gradient and to the fact that Na + ions are toxic to most plant cells. Rather, the depolarizing phase of action potentials is mediated by Cl − efflux channels and by Ca 2+ channels (3–6). Recent research has led to initial characterizations of Cl − /anion channel–encoding genes with unique structures (7–11).…”

Primary effect of bromoxynil to induce plant cell death may be cytosol acidification

“…Recently, this material was used in studies on the stress response of plants: mechanical stimulus (Shimmen 1996(Shimmen , 1997a(Shimmen , b, c, 2001bShepherd et al 2001;Kaneko et al 2005;Iwabuchi et al 2005), wounding (Shimmen 2001a(Shimmen , 2002(Shimmen , 2005(Shimmen , 2006 and aluminum (Takabatake and Shimmen 1997;Takano and Shimmen 1999).…”