ANALYSIS OF ELECTRIC AND ELECTROCHEMICAL CONNECTION BETWEEN LEAF-CELLS OF TRADESCANTIA-VIRGINIANA L THAT RESPONDS TO CO2 STRESS BY CHANGING INTRACELLULAR POTENTIAL

The intracellular potential of a Tradescantia virginiana L. leaf changed markedly in response to CO2 stress. To analyse this response, the intercellular connection of the leaf was investigated. When a limited area of a leaf was exposed to CO2, no response was obtained at a site separate from the CO2-exposed region. When the leaf was cut into various-sized fragments and exposed to CO2, each fragment size showed remarkably similar response patterns. However, when an electrochemical impulse was applied to one epidermal cell by injecting KCl electrophoretically, the same patterns of potential response were obtained from cells within a radius of 2 mm. Therefore, within this region, epidermal cells of T. virginiana are electrically short-circuited. In contrast, only a slight increase in the K+ concentration could be observed in neighbouring cells. Therefore, the cells appear to be electrochemically isolated from each other.