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Characterization of wound-induced electrical signaling and systemic molecular responses in etiolated pea (Pisum sativum) epicotyls
Abstract
Plants are subjected constantly to an array of physical and chemical stresses from pathogens, herbivores, and an ever changing environment. In response, plants synthesize compounds, induce genes, activate proteins (enzymes), change physiological processes and anatomical features. In many cases the response is not restricted to the site of injury or for the duration of the insult, but occurs throughout the plant (systemically) and with long-lasting results. The observation that a wound in one part of the plant induces a response elsewhere suggests the presence of a systemically transmitted signal. Intercellular electrical potentials, hydraulic pressure gradients, and biocompounds have been hypothesized and to varying extent investigated as the signalling mechanism in plants. A recent report by Wildon et al. (1992, Nature, 360:315) presented convincing evidence that electrical potentials were one of the primary signaling mechanisms in tomato. Calmodulin (CaM) is a calcium-binding regulatory protein involved in a plethora of molecular processes. A variety of environmental stimuli and intrusive wounding induces CaM gene expression in a number of plant species. This study was undertaken to assess the relationship between wound-induced electrical activity, CaM gene expression, and changes in the polysome population in etiolated pea epicotyls. Electrical shock and excision wounding of etiolated epicotyls did not elicit intercellular electrical signalling, although changes in polysomes and CaM gene expression were observed in the latter. Scorching and crushing of etiolated epicotyls induced an intercellularly propagated electrical signal, which was followed by marked changes in polysomes and CaM gene expression. Acetylsalicylate, a known inhibitor of wound-induced gene expression in other plants, inhibited scorch-induced electrical signaling, but had little effect on changes in polysomes and CaM gene expression. These results suggest that electrical activity may play a part in the systemic signaling response, but is not the primary signal.
Subject Area
Molecular biology|Cellular biology|Botany
Recommended Citation
Smith, Christopher Michael, "Characterization of wound-induced electrical signaling and systemic molecular responses in etiolated pea (Pisum sativum) epicotyls" (1995). ETD collection for University of Nebraska-Lincoln. AAI9615001.
https://digitalcommons.unl.edu/dissertations/AAI9615001