Methods and constructs for the introduction of multiple genes into plants
using a single transformation event are described. Constructs contain a
single 5' promoter operably linked to DNA encoding a modified intein
splicing unit. The splicing unit is expressed as a polyprotein and
consists of a first protein fused to an intein fused to a second protein.
The splicing unit has been engineered to promote excision of all
non-essential components in the polyprotein but prevent the ligation
reactions normally associated with protein splicing. Additional genetic
elements encoding inteins and additional proteins can be fused in frame
to the 5'-terminus of the coding region for the second protein to form a
construct for expression of more than two proteins. A single 3'
termination sequence, follows the last coding sequence. These methods and
constructs are particularly useful for creating plants with stacked input
traits and/or value added products.