What is Guttation?
lt is the loss of excess water in the liquid form through special water stomata called hydathodes present at the tip of the leaves of several herbaceous plants. The hydathodes are the openings at the tip of xylem elements. These are terminal pores
surrounded and subtended by some loose uncutinised non chlorophyllous cells having large intercellular spaces. These loose mass of cells are called epithem. The epithem is located at the end of the vein. The hydathodes do not have any regulatory organ-like guard cells. Guttation occurs at night when stomata remain close. The cause of guttation is excess root pressure.
The amount of exudate may be a few drops too many milliliters. That the drops which hang from the tip of leaves are not dewdrops and are really cell sap can be proved by chemical analysis. Dissolved minerals are found in the exudate. Guttation mainly occurs among herbs.
Exudation or bleeding takes place due to injury. Exudation of resin and latex from injured areas are the best examples. These should not be confused with guttation which is natural exudation. Bleeding results from cuts or injuries.
What is Transpiration?
Transpiration is the process of water movement through the body of plants and the process of evaporating unnecessary water from its upper parts, such as leaves, stems, and flowers. Like all organisms, plants also need an excretion system to discharge excess water from their bodies. The elimination of excess water from the plant’s body is transpiration. It is mainly caused by the stomates of leaves.
Difference between Transpiration and Guttation
| Transpiration | Guttation |
| 1. Usually occurs in the daytime. | 1. Usually occurs at night. |
| 2. Takes place through stomata. | 2. Takes place through water stomata. |
| 3. Water escapes as vapour. | 3. Water escapes as a liquid, which contains dissolved minerals. |
| 4. Regulated by the physiology of the cells. | 4. No regulatory mechanism exists. |
| 5. Takes place when the atmosphere is deficient in water vapour. | 5. Takes place when the air is humid. |
| 6. Excessive transpiration causes wilting. | 6. It never results in wilting. |
| 7. Transpiration does not cause any loss of minerals from the plant body. | 7. Guttation causes some loss of minerals. |