About Tendril

It is a kind of plant organ that is used for anchoring and supporting the vining system. It can be a modified structure of leaves, leaflets, leaf tips, or leaf stipules. They may also be derived from modified stem branches like in grapes. They are thin, thread-like growths present on the stem or leaves of climbing plants. Based on growth tendril are of two types they are: stem tendril and leaf tendril. And their growth is mainly towards the support with which they can attach themself for the support and this phenomenon is known as thigmotropism.

Function of Tendril

Some of the common function of tendril are discussed below:

  1. They are known to be modified portions of leaf, stem or petiole. 

  2. Their main function is to provide support to the plant as it climbs up a structure. By doing so they allow a plant to find a more suitable area to grow due to more light.

  3. When stems are modified into tendril they help plants to climb. 

  4. The Positions of tendril are different in different plants like in leaf, stem or even branches in few plants.  

Stem Tendril

When stems are modified into threadlike leafless structure then they are known as stem tendril. Their major role is for climbing purposes, they don't necessarily contain a branch. 

Further Stem Tendril Are Classified Into Different Types, They Are

Axillary: E.g., Passiflora

Extra-Axillary: E.g., Luffa

Apical Bud: E.g., Grapevine

Floral Bud: E.g., Antigonon

What is Thigmotropism?

It is a kind of curvature movement shown by a plant in response to a unilateral touch stimulus and can be observed in many climbers. In tendril climbers, the tendrils first show mutation, and as soon as their apices touch support, they move thigmotropic ally to turn around it.

Some of the common examples of tendril-producing plants are the grape, members of the squash or melon family (Cucurbitaceae), the sweet pea (Lathyrus odoratus), and the passion flowers (Passiflora species).

Explain the Role of Auxin in the Growth of Tendril

It is a kind of growth hormone which is generally synthesized at the shoot tip. It enhances the growth of cells so that plants can increase their length. As soon as the tendril comes in contact with any support system, auxin stimulates the cell to grow faster on the opposite side that’s why the tendril forms a coil around the support.

Some of the Common Examples of Auxin Based on Their Synthesis Are

  • Naturally occurring auxins: Indole acetic acid, indole ethanol, indole acetaldehyde.

  • Synthetic auxins: Naphthalene acetic acid, indole butyric acid, 2,4-dichlorophenoxyacetic acid.

FAQs (Frequently Asked Questions)

1. Explain different modifications of parts of plants that form tendril?

Plants that undergo modification for tendril formation are:

  1. In the case of pea plants, their terminal leaflets are modified to form a tendril. 

  2. In yellow Vetch, the whole leaf gets modified to form a tendril and their stipules enlarge themself for the photosynthesis process. 

  3. In case of the Pitcher plant, a specialised pitcher trap form tendril from one end. 

So, in all such plants, their major function is to anchor themself to any support system to provide proper growth to plant in the direction of sunlight. 

2. Name the plant in which stems are modified into tendril?

In pea plant i.e. Pisum sativum, their stem gets modified into tendril for the support system.

3. Who was the first to study tendril?

Charles Darwin was the very first to do a study of tendril and their movement.