Changes in some nitrogen fractions, protease and RNA depolymerase activity during induction by auxin of adventitious roots in tomato leaves cuttings

Abstract

On tomato leaf cuttings treated with 10<sup>-4</sup> M IAA for 24 h and then placed for 24 h in an incubation solution induces after 4 days the appearance of adventitious roots. Experiments with actinomycin D and chloramfenicol indicate that a period of 2-3 days is essential for the synthesis of protein specific for rooting. It was found that in this period a number of characteristic changes in metabolism occurs in cuttings treated in this way. A decrease of insoluble nitrogen (Np) in the leaf blades was noted with simultaneous synthesis of this fraction and an increase of the soluble nitrogen fraction amount (Ns) in the basal pant of the petiole. In this period an enhanced activity of proteolytic enzymes is observed in the blades of leaf cuttings treated with IAA, and a decrease of activity of these enzymes and of RNA depolymerases in the basal part of the petiole. It is suggested that treatment of the cuttings with IAA solution elicits in them a number of changes in metabolic processes, leading as consequence to initiation of adventitious roots.