Auxin-like Growth Activity of 3-Phenylpropionitrile from Water-Cress (Nasturtium officinale R. Br.)

Solutions of 3-phenylpropionitrile (PPN) and 3-phenylpropionicacid (PPA) exhibited auxin-like plant growth activity by stimulatingelongation of sections cut from wheat coleoptiles and garden-cresshypocotyls. Elongation of sugar-beet hypocotyl sections wasstimulated by PPA but not by PPN. Although PPA stimulated elongationof pea-epicotyl sections after 19 h incubation, most concentrationsof PPN did not show activity until 70 h. PPN generally stimulatedadventitious root formation on hypocotyls of garden-cress andsugar-beet, and on epicotyls of pea seedlings whereas dilutesolutions of PPA were inactive and concentrated solutions weretoxic. Steam distillates of water-cress plants contained a substancewith auxin-like growth activity and chromatographic propertiessimilar to PPN. Nasturtium officinale R. Br. water-cress, 3-phenylpropionitrile, 3-phenylpropionic acid, auxins