EFFECTS OF GIBBERELLIN AND AUXIN ON THE EXTENSIBILITY OF THE PEA STEM

Abstract

Excised pieces of etiolated Alaska pea stem were pulled longitudinally or transversely, and elongation or bending was measured. Pieces treated with IAA were stretched conspicuously when longitudinal force was applied, and continued elongating under the force at approximately the same rate as without it. Control pieces behaved in a similar way, but on a smaller scale. Pieces treated with gibberellin scarcely elongated under the force, but elongated without it. IAA-treated stem pieces were bent by transverse force more easily, and gibberellin-treated ones less easily than control.