Hierarchies and Textures in Supergravity Unification

It is proposed that supergravity unified models possess, in addition to the hidden and the visible sectors, a third sector which contains exotic matter with couplings to the fields of both the visible and the hidden sectors, and that its elimination leads to quark-lepton textures at the grand unified theory (GUT) scale with a hierarchy in powers of M_G/M_P. Simultaneously the GUT mass is computed in terms of the Planck/string scale. Textures in the Higgs triplet sector are computed using a complete set of texture sum rules, and it is shown that they modify predictions of proton decay in unified models.