Guttation: Have you ever seen the shining crystal-like water droplets in the night-time or early in the morning? You must have noticed these water droplets are present at the tip and the margins of the leaves. These water droplets are formed because of a process called Guttation. When we look at a plant, we assume that it works simply.

It takes in water and uses photosynthesis to grow, but they also have a secret life where their survival depends on the balance of water and nutrients. Furthermore, it is important to note that Guttation occurs at night when the soil is moist and the roots absorb water. In this article, we will provide you with all the detailed information about Guttation. Continue reading to find more!

Definition of Guttation

Guttation is defined as the loss or excretion of water in the form of liquid droplets from the tips and margins of the leaves. Or in other words, Guttation is the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses. Guttation was first studied by Bergerstein in \(1887.\)

Fig: Presence of Water Droplets at the Tips and the Margins of the Leaf

Guttation Process

1. All plants do not show Guttation. It is restricted to about \(345\) genera of herbaceous and some woody plants like garden nasturtium, oat, and other cereals, balsam, tomato, cucurbits.
2. All these plants mentioned above grow in warm, moist soils with a humid environment or when warm days are followed by cool nights.
3. Guttation is sometimes confused with dew droplets that condense from the atmosphere onto the plants surface.
4. At night time, transpiration usually does not occur because most plants have their stomata closed.
5. In general, the guttation process is observed the most when the transpiration is suppressed, and relative humidity is maximum, as seen during the night.
6. When the level of moisture is very high in the soil, water enters the roots because the water potential of the roots is lower than in the soil.
7. The fluid coming out of Guttation often contains a variety of organic and inorganic compounds, mainly sugars and potassium.
8. Rather than transpiration pull, root pressure provides the impetus for this flow of impure liquid during Guttation.
9. Thus, water accumulates in the plants, creating a slight root pressure that forces some water to exude through specialised pores at the tips and the vein endings (margins) of the leaves called hydathodes (or water stomata).

Guttation: Structure of Hydathode

Hydathodes or water stoma are the specialised structures involved in the guttation process. They are different from normal stomata.

1. Each hydathode consists of a group of loosely arranged colourless parenchymatous cells called epithem.
2. Hydathode lies over the tip of a vascular strand and communicates with the outside through a permanent pore in the epidermis called a water pore or water stoma.
3. They are made of a group of living cells with numerous intercellular spaces filled with water. However, in most cases, they do not have chloroplasts.

NCERT Solutions for Class 11 Biology Chapter 17

NCERT Solutions for Class 11 Biology

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Water lost in Guttation is impure water, i.e., a dilute solution of different inorganic and organic salts. As the water evaporates, the inorganic and organic salts dissolved in guttated liquid accumulate over the surface, forming a sort of rusty white layer. This may remain permanently and eventually cause plasmolysis resulting in the death of underlying tissues.

Difference Between Stomata and Hydathode

Below we have provided the difference between Stomata and Hydathode:

Stomata	Hydathode
Stomata occur on the epidermis of leaves, young stems, etc.	Hydathodes generally occur at the tip or margins of leaves of those plants that grow in moist shady places.
Two kidney-shaped guard cells guard the stomatal aperture.	The aperture of the hydathode is surrounded by a ring of cuticularised cells.
Modified epidermal cells or subsidiary cells surround these two guard cells.	The subsidiary cells are absent.
The opening and closing of the stomatal aperture are regulated by guard cells and internal factors.	Hydathode pores always remain open. There is no closing mechanism for water stoma.
These structures are involved in transpiration and exchange of gases as well.	These structures are not involved in gaseous exchange.

Fig: Structure of Stomata

Fig: Structure of Hydathode

Difference between Guttation and Transpiration

We have provided the difference between Guttation and Transpiration below:

Transpiration	Guttation
It usually occurs during the day.	It usually occurs at night or early in the morning.
Water is given out in the form of water vapours.	Water is given out in the form of a liquid.
Several factors are responsible for this process.	This primarily occurs due to higher root pressure.
Water comes out in the pure form.	Water droplets consist of various organic and inorganic salts dissolved in them. So it is not pure.
It occurs through stomata, lenticels or cuticles.	It occurs through hydathodes only.
It is a controlled phenomenon.	It is an uncontrolled phenomenon.

Significance of Guttation

The significance of Guttation is as follows:

1. It helps the plants to dispose of the unwanted solutes.
2. It helps the plants to improve the acquisition of nutrients.
3. It helps in maintaining water balance for the proper growth and development of the plant body.
4. It helps in the progressive development of hydrostatic pressure that helps to pump water up to the leaves.
5. Guttation fluid helps for non-invasive measurements and organic and inorganic chemical quantification.

Summary

Guttation is defined as the loss or excretion of water in the form of liquid droplets from the tips and margins of the leaves. Guttation is sometimes confused with dew droplets that condense from the atmosphere onto the plants surface. At night time, transpiration usually does not occur because most plants have their stomata closed.

In general, the guttation process is observed the most when the transpiration is suppressed and relative humidity is maximum, as seen during the night. Guttation helps the plants to dispose of the unwanted solutes. It is also important to note that Guttation fluid helps in non-invasive measurements and inorganic chemical quantification. Furthermore, it happens through hydathodes only.

Other important Biology articles:

Circulatory System	Lymphoid Organs
Respiration and Circulation	Lymphatic System
Circulatory Disorders	Blood Groups
Blood	Blood Vessels

FAQs on Guttation

Q.1. What is Guttation?
Ans: Guttation is defined as the process of loss or excretion of water in the form of liquid droplets from the tips and margins of the leaves.

Q.2. What is the difference between transpiration and guttation?
Ans: Transpiration usually occurs during the day, whereas Guttation usually occurs at night or early in the morning. Transpiration occurs through stomata, lenticels or cuticles whereas, guttation occurs through hydathodes only.

Q.3. Why is Guttation in plants important?
Ans: a. It helps in the disposal of unwanted solutes by the plants.
b. It helps to improve the acquisition of nutrients by the plants.
c. It helps to maintain the water balance for the proper growth and development of the plant body.

Q.4. Is guttation good or bad?
Ans: Guttation is completely a natural phenomenon that is not at all harmful to plants. However, suppose more amount of fertilisers is used for the plant. In that case, the minerals from the fertilisers get deposited on the tips and the margins of the leaves in the form of white rust after the water droplets get evaporated.

Q.5. What causes Guttation?
Ans: Guttation is caused when the transpiration is suppressed and relative humidity is maximum, as seen during the night. Primarily, root pressure is responsible for Guttation.

We hope this detailed article on Guttation helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.