THE INVOLVEMENT OF THE GENE TRP FROM AGROBACTERIUM-TUMEFACIENS IN THEAUXIN-INDEPENDENT GROWTH OF TRANSFORMED CARROT CELLS

The activity of tryptophan synthase (TrpS) in the suspension culture o f carrot (Daucus carrota L.) cells transformed with Agrobacterium tume faciens, strain 8628, was 5-10 times higher that in wild-type cells. T he contents of tryptophan and IAA were also higher in transformed cell s. Elution patterns of TrpS from a DEAE-Toypearl column were similar f or the bacterial TrpS and TrpS from transformed plant cells. Denaturin g PAGE demonstrated the presence of two isozymes of TrpS in bacterial and transformed carrot cells and only a single isozyme in wild-type ce lls. TrpS from transformed cells cross-reacted with antibodies raised against bacterial TrpS. These antibodies inhibited the activity of Trp S from transformed cells more drastically than that from nontransforme d cells. In wild-type cells, indole was a more effective precursor of auxin than tryptophan. The conclusion was drawn that the agrobacterial trp gene was expressed in transformed carrot cells.