Automorphism groups of truncated polynomial algebras

The automorphism group Aut (A*) of a finitely generated graded commutative algebra A* over a field F of characteristic zero has been studied. In case A* is free and the set S of generators satisfies the condition that the product of any two elements of S is outside of S, then we show that Aut (A*) is isomorphic to a product of general linear group over F. On the other hand, if A* is truncated, then without any condition on S we prove that Aut (A*) is the direct product of certain Wreath products.