Growth regulating action of isoprothiolane in plants. V. Interactions between RNA, protein synthesis inhibitors and isoprothiolane on adventitious root formation in stem segments of pulse crops.

Abstract

Isoprothiolane (diisopropyl-1, 3-dithiolan-2-ylidenmalonate, IPT; FUJIONE(R)) promoted adventitious root formation of kidney bean (Phaseolus vulgaris L.) hypocotyl more than IAA under by the 24h treatment just after the segment preparation. IPT also enhanced rooting in azuki bean (Phaseolus angularis L) epicotyl segments, in which the number of dividing cell in the root primordia increased. Actinomycin D and cycloheximide were examined for their effects on root formation in the presence or absence of pre-treatment with IPT. Cycloheximide at 10-4M completely inhibited rooting of segments when applied for 2h; however, pre-treatment with 5×10-4M IPT alleviated its inhibitory effect. Actinomycin D, on the other hand, did not inhibit rooting at the concentration from 10-8M to 10-5M. There was no interaction between IPT and actinomycin D on rooting. These results may indicate that IPT enhances adventitious root formation in association with the specific protein synthesis for the initiation of root primordia.