  In the near future, Parker Solar Probe will put theories about the dynamics
and nature of the transition between the solar corona and the solar wind to
stringent tests. The most popular mechanism aimed to explain the dynamics of
the nascent solar wind, including its heating and acceleration is
magnetohydrodynamic (MHD) turbulence. Most of the previous models focus on
nonlinear cascade induced by interactions of outgoing Alfv\'en waves and their
reflections, ignoring effects that might be related to perpendicular
structuring of the solar coronal plasma, despite overwhelming evidence for it.
In this paper, for the first time, we analyse through 3D MHD numerical
simulations the dynamics of the perpendicularly structured solar corona and
solar wind, from the low corona to 15 R_Sun. We find that background
structuring has a strong effect on the evolution of MHD turbulence, on much
faster time scales than in the perpendicularly homogeneous case. On time scales
shorter than nonlinear times, linear effects related to phase mixing result in
a 1/f perpendicular energy spectrum. As the turbulent cascade develops, we
observe a perpendicular (parallel) energy spectrum with the power law index of
-3/2 or -5/3 (-2), a steeper perpendicular magnetic field than velocity
spectrum, and a strong build-up of negative residual energy. We conclude that
the turbulence is most probably generated by the self-cascade of the driven
transverse kink waves, referred to previously as `uniturbulence', which might
represent the dominant nonlinear energy cascade channel in the pristine solar
wind.
