VirB/D4-dependent protein translocation from Agrobacterium into plant cells

The Agrobacterium VirB/D4 transport system mediates the transfer of a nucle oprotein T complex into plant cells, Leading to crown gall disease. In addi tion, several Virulence proteins must somehow be transported to fulfill a f unction in planta. Here, we used fusions between Cre recombinase and VirE2 or VirF to directly demonstrate protein translocation into plant cells. Tra nsport of the proteins was monitored by a Cre-mediated in planta recombinat ion event resulting in a selectable phenotype and depended on the VirB/D4 t ransport system but did not require transferred DNA.