Abstract
Localized heat wounding of tomato plants triggered rapid changes in growth and in electrical activity. The growth alterations were manifested as a transient increase in growth (petiole elongation), followed by a massive, long-lasting growth reduction. The electrical potential changes consisted of a wave of depolarization and re-polarization, i.e., a variation potential (VP). The tissue deformation apparently resulted from a pressure surge rapidly transmitted through the xylem, and preceded the changes in electrical potential. Externally-applied pressure mimicked flame wounding by triggering an electrical response resembling a VP. Our findings suggest that the VP results from a pressure surge in the xylem causing change in activity of mechanosensitive ion channels or pumps in adjacent living cells. The ensuing ion fluxes evoke plasma membrane depolarization, monitored extracellularly as a VP.

This publication has 0 references indexed in Scilit: