To transport water and mineral salt for the plant. Plants have two types of tissues in them. One is Xylem. The other is phloem. Xylem has cells, which are thick and hard. In trees, xylem is the wood in the middle.
As soon as they are formed, they die. Xylem is essential because the water and nutrients that they carry are vital for the plant to live. All parts of a plant, including the root and the stem, have xylem. Each xylem has four types of cells in them.