The enzymatic transformation of leaf-movement factor in Lespedeza cuneata G. Don controlled by a biological clock

We have shown that enzymatic transformation of potassium lespedezate (leaf-opening substance) to potassium 4-hydroxyphenylpyruvate in a nyctinastic plant, Lespedeza cuneata G. Don, controls the leaf-movement of the plant. By this transformation in the evening, the balance of concentration between leaf-opening substance and leaf-closing substance is inversed through a day. A biological clock should control the leaf-movement by activation or expression of the enzyme concerned in this step.