Effect of iron deficiency stress on leaves movements and electrical potentials in mimosa (Mimosa pudica L.)

Abstract

The aim of the studies was to trace the motorical and electrical activity of the mimosa (Mimosa pudica L.) grown under conditions of iron deficiency. The speed of leaf folding was measured (motorical activity) and the action potential induced with thermic and light stimuli and turgorin (electrical activity was recorded). It was found that the iron deficiency caused acidification of medium and the maximum of the process coincided with the period when the young leaves were turning green. Chlorotic mimosa leaves, not detached from the plant, showed an increased motorical activity. Motorical and electrical activity of the leaves were inhibited by an inhibitor of the plasmalemma redox systems - quinacrine, and stimulated by blue light. Leaf movement factor - turgorin - caused a hypersensitivity of chlorotic plants. It follows from the studies that the observed effects resulted from the adaptation of mimosa to the iron stress. The adaptation was a result of formation of new plasmalemma redox systems (turbo-reductase), responsible for maintaining high energy levels in the cells.