The phloem transfers food from the stem to the roots when the plant can produce food and send it to storage areas. On days when there isn’t enough sunlight etc food cannot be produced by the plant, therefore food is transferred from the storage areas (viz. the roots) to the stem.
Transport of materials in phloem
- Phloem tissue helps in the transport of food
- Food is transported in both upward and downward directions.
- Transport of food in phloem requires energy in the form of ATP.
- Metabolic inhibitors inhibit phloem transport.
- Phloem tissues are composed of four elements: sieve tube elements, companion cell, phloem fibres, and phloem parenchyma and serve in the translocation of organic nutrients.