Please explain the concept of diffusion pressure deficit in plant transportation

it is generally the reduction in diffusion pressure of water in solution or cell over its pure state due o presence of solutes in it..in other words it is the algebraic sum of all forces tending to cause water to move into a plant cell.diffusion pressure deficit= osmotic pressure- turgor pressure....water always moves from low DPD to high DPD....hope this helps u :):)