Xylem and phloem are the conducting tissues of the vascular strands. Their main role is in the transportation of food, minerals, and water. Xylem is the tissue which is responsible for the transport of water in plants while the phloem is responsible for the transfer of food and nutrients in the plant. These tissues are responsible for the conduction of substances in plants from top to bottom and thus helps in transporting materials to and from top and bottom of the plant.