Question

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

Answer 1

Translocation is the movement of materials from leaves to other tissues throughout the plant. Plants produce carbohydrates (sugars) in their leaves by photosynthesis, but non-photosynthetic parts of the plant also require carbohydrates and other organic and non-organic materials. Carbohydrates are mainly transported in the phloem in the form of sucrose. The cell membrane of the sieve cells contains pump proteins that actively convey sucrose into the vascular pathways. Mass Flow Hypothesis is the best-supported theory to explain the movement of sap through the phloem. Movement of phloem sap occurs by bulk flow (mass flow) from sugar sources to sugar sinks.