What is meant by translocation with respect to transport in plants?
Hint: Translocation is the transportation of substances to a long-distance via a vascular system. The transportation of substances in translocation may be unidirectional or multidirectional with the help of xylem and phloem.
Complete Answer: Translocation helps in the long-distance transport of water and minerals through the xylem and organic nutrients through the phloem. In the case of xylem transport, it takes place unidirectional, from root to other parts of the plant. The main region where the utilization of minerals elements take place is the apical region, lateral meristems, young leaves, developing flowers, fruits and seeds. The phloem transport mainly takes place from leaves because the synthesis of carbohydrate takes place in leaves through photosynthesis and from leaves these carbohydrates get transported to other parts of plants that utilize and store food. Synthesis of carbohydrate takes place from source and utilization or storage of carbohydrate takes place in the sink region. The channel of transport in phloem is mainly sieve tubes and sieve cells. The long column holes at the end of the sieve tube cells get connected with companion cells and help in the transportation of ATP, proteins and other nutrients. Due to changing direction of the source and sink phloem show bidirectional movement. Phloem transport mainly deals with water and sucrose with sugar, hormones and amino acids.
Note: In case any plant part is in the senescence phase then transportation of mineral ions takes place from older dying leaves to younger leaves before the leaf falls and this process is known as remobilisation. Remobilisation takes place in metals like phosphorus, sulphur, nitrogen and potassium. The source and sink region may get reversed depending on the season or plant needed.