Leaf-opening substance of Mimosa pudica L.; chemical studies on the other leaf movement of mimosa

Abstract

We have isolated mimopudine ( 1) as a leaf-opening substance of mimosa that keeps the leaves open even at night. 1 was quite effective for leaf-opening of Mimosa pudica L. at 2 ×10 −5 M at night, but not effective for other nyctinastic plants even at 1 ×10 −2 M. Interestingly, the leaves kept open at night with 1 were sensitive to stimulus by touch. This result suggests that 1 is effective only for the obstruction of slow nyctinastic leaf-closing movement, but not effective for the rapid thigmonastic movement. Therefore, the slow nyctinastic movement of mimosa is controlled by a different mechanism from that of the rapid thigmonastic movement.