Is membrane potential involved in calmodulin gene expression after external stimulation in plants?

In Bidens pilosa (cv. radiata), a non-injurious stimulus induces a local and transient change in membrane potential, and an injurious stimulus induces a transmitted electrical signal described as the combination of an action potential and a slow wave. We have studied calmodulin gene expression after these stimuli. When the stimulus is non-injurious, calmodulin mRNA accumulation is only increased in the stimulated region. In contrast, when the stimulus is injurious, mRNA accumulation takes place in both wounded and distant, unwounded tissue. We propose that the slow wave plays a role in the long-distance transmission of a wound-induced information in plants.