Explain pressure flow hypothesis of translocation of sugars in plants.

* The pressure flow hypothesis explains translocation of sugars.
* It was proposed by Munch.
* Glucose is prepared at the source is converted to sucrose. 
* The sucrose moved into the companion cells and then into the sieve tube by active transport. It leads to decrease in water potential in seive tubes.
* Water in the adjacent xylem moves into the phloem by osmosis.
* As osmotic pressure builds up, the phloem sap moves to areas of lower pressure(sink).
* At the sink, incoming sugars are actively transported out of the phloem.
* Water potential increases in the phloem.
* Water moves out of the phloem by osmosis.