Ethionine and Auxin-Action in Avena Coleoptile

Abstract

The rate of transfer of methyl groups from methionine to the hot-water-soluble fraction of Avena coleoptile cell walls is strongly inhibited by ethionine. The auxin-induced increase in methylation can be prevented entirely by ethionine. This inhibition occurs within 1 hour after addition of ethionine. Ethionine causes an immediate inhibition of the reversible elongation of the tissues. Irreversible elongation is strongly inhibited only after 3-6 hours. EDTA will reverse the inhibition of reversible but not irreversible elongation. It is suggested that the inhibition of methylation may be the cause of the inhibition of reversible elongation while an inhibition of protein synthesis may lead to the inhibition of irreversible elongation.