 Davies research has been on the role of plant hormones in whole plant physiology, including stem growth, whole-plant senescence, tomato ripening and potato tuberization.In 1866, Gregor Mendel, the father of genetics, demonstrated that height in peas was controlled by a single factor.More than a century later, Davies discovered that Mendel's stem length gene ("Le") in peas encoded a gibberellin 3β-hydroxylase.