Requirement of RNA for the Auxin‐induced Elongation of Oat Coleoptile

Abstract

Abstract Using etiolated oat coleoptile segments the following results were obtained. Actinomycin D pretreatment for one hour produced about 50 per cent inhibition of RNA synthesis (labeled uracil incorporation), but the elongation caused by IAA was not inhibited in the following 5 hours at least. Actinomycin D pretreatment for three hours produced about 75 per cent inhibition of RNA synthesis and almost complete inhibition of subsequent IAA‐induced elongation, which is accompanied by the inhibition of IAA‐induced increase in cell wall extensibility. The inhibiting effect of actinomycin D seemed to be reduced when IAA was given within a certain period.