  We propose a way to introduce matter fields transforming in arbitrary
representations of the gauge group in noncommutative U(N) gauge theories. We
then argue that in the presence of supersymmetry, an ordinary commutative SU(N)
gauge theory with a general matter content can always be embedded into a
noncommutative U(N) theory at energies above the noncommutativity mass scale
M_{NC} ~ \theta^{-1/2}. At energies below M_{NC}, the U(1) degrees of freedom
decouple due to the IR/UV mixing, and the noncommutative theory reduces to its
commutative counterpart. Supersymmetry can be spontaneously broken by a
Fayet-Iliopoulos D-term introduced in the noncommutative U(N) theory. U(1)
degrees of freedom become arbitrarily weakly coupled in the infrared and
naturally play the role of the hidden sector for supersymmetry breaking. To
illustrate these ideas we construct a noncommutative U(5) GUT model with
Fayet-Iliopoulos supersymmetry breaking, which reduces to a realistic
commutative theory in the infrared.
