Question

What is the term used for long distance movement of carbohydrates in plants ? How and in what form do the carbohydrates synthesized in the leaves, reach long distance parts in a plant?

Answer 1

The food material synthesized in the leaves is translocated to the different regions of the plants through the phloem either by cytoplasmic streaming hypothesis or by mass flow hypothesis. 

(i) According to mass flow hypothesis proposed by Munch (1926), the translocation of food takes place from leaves to the storage organs of the plant. 

(ii) The food in the form of glucose is prepared by leaves by the process of photosynthesis. 

(iii) It increases the osmotic potential. As a result, the water from the xylem cells enters into the leaf cells by increasing turgor pressure. 

(iv) At the other end or in fruits and seeds, there is a low concentration of sugar which results in a low turgor and osmotic pressure. This difference in the pressure occurs on the two extreme sides i.e., on one side there are leaves and on the other side there are other organs of the plant.