Non-Commutative GUTs, Standard Model and C,P,T properties from Seiberg-Witten map

Noncommutative generalizations of Yang-Mills theories using Seiberg-Witten map are in general not unique. We study these ambiguities and see that SO(10) GUT, at first order in the noncommutativity parameter \theta, is unique and therefore is a truly unified theory, while SU(5) is not. We then present the noncommutative Standard Model compatible with SO(10) GUT. We next study the reality, hermiticity and C,P,T properties of the Seiberg-Witten map and of these noncommutative actions at all orders in \theta. This allows to compare the Standard Model discussed in [5] with the present GUT inspired one.