  We study operator mixing, due to planar one-loop corrections, for composite
operators in D=4 supersymmetric theories. We present some N=1,2 Yang-Mills and
Wess-Zumino models, in which the planar one-loop anomalous dimension matrix in
the sector of holomorphic scalars is identified with the Hamiltonian of an
integrable quantum spin chain of SU(3) or SU(2) symmetry, even if the theory is
away from the conformal points. This points to a more universal origin of the
integrable structure beyond superconformal symmetry. We also emphasize the role
of the superpotential in the appearance of the integrable structure. The
computations of operator mixing in our examples by solving Bethe Ansatz
equations show some new features absent in N=4 SYM.
