Studies on the Organ of Production of the Natural Gibberellin Factor in Higher Plants.

Abstract

It was demon-strated that applied gibberellin can replace almost completely the stem tip in promoting the elongation of the subapical region of the pea stem. This effect of the gibberellin cannot be replaced by IAA. It is concluded that the natural gibberellin factor of the pea plant is produced in the stem tip. Gibberellin cannot replace either the roots or cotyledons in the promotion of stem growth. Grafting experiments indicate that the natural gibberellin does not reach the stock across a graft, at least until after tissue union has occurred.