Initial stages of low-temperature induction of cabbage cold shock protein gene csp5.
Some stages of low-temperature signal transduction causing appropriate cold stress response in plants are considered. The effects of Ca2+ chelators, Ca2+ channel blockers, and protein kinase inhibitors on protoplasts and plants of cabbage suggest that the initial stages of cold signal transduction are the change in membrane fluidity followed by the activation of calcium channels and elevation of Ca2+ influx into the cytoplasm. Increased concentration of Ca2+ in cytoplasm activates calcium-dependent protein kinase most likely participating in induction of transcription factors necessary for the expression of cold-regulated genes, in particular csp5. The protein kinase inhibitors staurosporine and wortmannin insignificantly repress the expression of csp5.