The involvement of calmodulin and protein kinases in the upstream of cytosolic and nucleic calcium signaling induced by hypoosmotic shock in tobacco cells

Abstract

Changes in Ca concentrations in cytosol ([Ca]) or nucleus ([Ca]) may play some vital roles in plants under hypoosmotic shock (Hypo-OS). Here, we observed that Hypo-OS induces biphasic increases in [Ca] and [Ca] in two tobacco cell lines (BY-2) expressing apoaequorin either in the cytosol or in the nucleus. Both [Ca] and [Ca] were sensitively modulated by the inhibitors of calmodulin and protein kinases, supporting the view that calmodulin suppresses the 1 peaks and and protein kinases enhance 2 peaks in [Ca] and [Ca]. Data also suggested that the 1 and 2 events depend on the internal and extracellular Ca sources, respectively.

The Mechanosensitive Ion Channel MSL10 Potentiates Responses to Cell Swelling in Arabidopsis Seedlings

“…We note that most previous reports of [Ca 2+ ]cyt response to hypo-osmotic shock describe a biphasic response (Takahashi et al, 1997b;Pauly et al, 2001;Hayashi et al, 2006;Shih et al, 2014). However, these responses vary widely in timescale and relative peak heights, and in some cases a monophasic response is observed (Takahashi et al, 1997a;Kurusu et al, 2012a;Nguyen et al, 2018). These differences can be attributed to differences in the tissue used, the extent of osmotic down shock, or the timescale of measurement.…”

“…These rapid responses are only the beginning of the plant cell's response to cell swelling. A transient increase in cytoplasmic calcium ([Ca 2+ ]cyt) in response to cell swelling has been documented in cultured tobacco, rice and Arabidopsis cells (Takahashi et al, 1997b;Cazalé et al, 1998;Cessna et al, 1998;Cessna and Low, 2001;Pauly et al, 2001;Nakagawa et al, 2007;Kurusu et al, 2012a;Kurusu et al, 2012b;Nguyen et al, 2018), Arabidopsis leaves (Hayashi et al, 2006), and Arabidopsis root tips (Shih et al, 2014). Cell swelling also produces a burst of reactive oxygen species (ROS) (Yahraus et al, 1995;Beffagna et al, 2005;Rouet et al, 2006) and leads to the activation of mitogen-activated kinases (Takahashi et al, 1997a;Cazalé et al, 1998;Droillard et al, 2004).…”

The Mechanosensitive Ion Channel MSL10 Potentiates Responses to Cell Swelling in Arabidopsis Seedlings

“…The [Ca 2+ ] cyt response in the msl10-3G mutant was significantly higher than the wild type at 5.6 s. Thus, cell swelling triggers a rapid and transient increase in [Ca 2+ ] cyt and MSL10 is required for this response. Although most previous reports of [Ca 2+ ] cyt response to hypoosmotic shock describe a biphasic response [11,15,20,21], these responses vary widely in timescale and relative peak heights, and in some cases, a monophasic response is observed [14,18,25]. These differences can be attributed to differences in the tissue used, the extent of osmotic down shock, and the timescale of measurement.…”

“…There are both immediate and delayed responses to such cell swelling. A transient increase in cytoplasmic calcium ([Ca 2+ ] cyt ) in response to hypo-osmotic shock has been documented in cultured tobacco, rice and Arabidopsis cells [11][12][13][14][15][16][17][18][19], Arabidopsis leaves [20], and Arabidopsis root tips [21]. Hypo-osmotic shock also produces a burst of reactive oxygen species (ROS) [22][23][24] and leads to the activation of mitogen-activated kinases [10,12,25] and other stress responses [26][27][28][29].…”

Ultrasound-Enhanced Chemiluminescence for Bioimaging

“…Besides being widely employed for monitoring of superoxide, coelenterazine and its analogs have found wide applications as prosthetic groups of various photoproteins like mnemiopsin, aequorin, phialidin obelin, and beroverin. Of all the above mentioned photoproteins, aequorin is widely used for measuring intracellular calcium and in immunoassay applications (Nguyen et al, 2018;Feno et al, 2019). Coelenterazine has been used often in cancer imaging.…”