Anticotyledon factor: Competitive inhibitors of the action of dihydroconiferyl alcohol in stimulating gibberellic acid-induced lettuce hypocotyl elongation

The lettuce cotyledon factor, dihydroconiferyl alcohol, synergisticallyenhanced the stimulating effect of gibberellic acid (GA₃) onhypocotyl elongation of decotylized lettuce seedlings. The actionof dihydroconiferyl alcohol was inhibited by 3-(3,4-dimethoxy-phenyl)propan-l-ol, 3-(3-hydroxy-4-methoxyphenyl) propionic acid, methyl-p-methoxycinnamate,trans-cinnamic acid, p-coumaric acid, ferulic acid, caffeicacid, and synapic acid. Kinetic studies with Lineweaver-Burkplots indicated that these compounds were competitive inhibitorsof dihydroconiferyl alcohol. These inhibitors were termed anticotyledonfactors. The action of dihydroconiferyl alcohol was not influencedby phenylalanine, tyrosine, p-coumaryl alcohol and coniferylalcohol. (Received March 28, 1977; )