Explain pressure flow hypothesis of translocation of sugars in plants.
The mesophyll cells of the leaves are sites for the continuous production of food in form of glucose. The source cells are located in phloem and they receive the food in converted form of glucose, that is sucrose. The hydrostatic pressure in the phloem rises because water contained in the xylem vessels moves to the nearest phloem. This leads to movement of sucrose via the sieve cells of the phloem. Hydrostatic pressure in the sink cells is reduced because sucrose already found in sink region converts into starch or cellulose. And as a result of this, sugars are translocated from sink cells to source cells due to the difference in pressure created in them.
