Gibberellin and growth in isolated wheat embryos.

Gibberellic acid promoted elongation growth in the coleoptiles and leaves of embryos from gamma-irradiated wheat grains whether the embryos were isolated or attached to the endosperm. Thus gibberellic acid affected this growth directly rather than indirectly through an effect upon endosperm. However, root growth was promoted by gibberellic acid only on embryos attached to endosperm, suggesting an indirect effect of gibberellic acid upon growth.