The Effect of CCC and Amo‐1618 on Growth, Catalase, Peroxidase and Indoleacetic Acid Oxidase Activity of Young Barley Seedlings

Barley seedlings were grown in darkness on filter paper saturated with phosphate buffer or CCC and Amo‐1618 buffered solutions. The effects of CCC and Amo‐1618 on growth, catalase, peroxidase and lAA‐oxidase were studied on coleoptile and primary leaves. Both growth‐retarding chemicals cause an inhibition of growth, Amo‐1618 being more effective than CCC. They have no effect on catalase activity. Increasing concentrations of CCC and Amo‐1618 progressively stimulate peroxidase and IAA‐oxidase activities (Amo‐1618 more than CCC). The enzymatic activity in short‐treated plants is higher than in the corresponding control plants of the same height. It is proposed that CCC and Amo‐1618 exert their effect on the growth of barley by acting on auxin catabolism.