  We performed 3D MHD simulations of planet migration in stratified disks using
the Godunov code PLUTO, where the disk is turbulent due to the
magnetorotational instability. We study the migration for planets with
different planet-star mass ratios $q=M_{p}/M_{s}$. In agreement with previous
studies, for the low-mass planet cases ($q=5\times10^{-6}$ and $10^{-5}$),
migration is dominated by random fluctuations in the torque. For a Jupiter-mass
planet $(q=M_{p}/M_{s}=10^{-3}$ for $M_{s}=1M_{\odot})$, we find a reduction of
the magnetic stress inside the orbit of the planet and around the gap region.
After an initial stage where the torque on the planet is positive, it reverses
and we recover migration rates similar to those found in disks where the
turbulent viscosity is modelled by an $\alpha$ viscosity. For the
intermediate-mass planets ($q=5\times10^{-5}, 10^{-4}$ and $2\times10^{-4}$) we
find a new and so far unexpected behavior. In some cases they experience
sustained and systematic outwards migration for the entire duration of the
simulation. For this case, the horseshoe region is resolved and torques coming
from the corotation region can remain unsaturated due to the stresses in the
disk. These stresses are generated directly by the magnetic field. The
magnitude of the horseshoe drag can overcome the negative Lindblad contribution
when the local surface density profile is flat or increasing outwards, which we
see in certain locations in our simulations due to the presence of a zonal
flow. The intermediate-mass planet is migrating radially outwards in locations
where there is a positive gradient of a pressure bump (zonal flow).
