Plant Movements Influenced by Light Stimulation, These are Types and Examples

YOGYAKARTA - Have you ever heard of the term phototropism? According to the book "Aku Kenal: Activities for Children Aged 4-5 Years" published by Grasindo, phototropism is the movement of plants influenced by light. For a clearer understanding, see the explanation of phototropism and examples of its movements below.

Plant Movements Influenced by Light Stimuli

Phototropism is the movement of plants caused by light and is of two types: positive and negative phototropism. According to the book "Si Teman: Biologi SMP VIII" by the Matrix Media Literata Team, positive phototropism is the movement of plant parts toward light, while negative phototropism is the movement of plant parts away from light.

Positive phototropism can be found in the movement of sprout tips or growing plant tips, specifically the hormone auxin. The side exposed to light will experience stunted growth, while the area unexposed will grow normally. Negative phototropism can be found in the growth of root tips away from light.

Examples of Phototropic Movement

An example of phototropism can be found in the growth of grass coleoptiles toward light. The coleoptile is the first leaf to grow on a monocot plant, which serves to protect the newly developing embryo.

Phototropism, also known as heliotropism, is closely related to the growth substance found at the tip of the plant (auxin). On the side of the stem exposed to light, the growth substance is present in lower amounts than on the side not exposed to light. This results in slower growth on the side of the stem exposed to light than on the side not exposed to light. The plant stem will also bend toward the light.

Other Types of Tropism Movement

Quoted from the Journal of the Use of Learning Media with Lectora-Based Programs to Improve Science Interest and Learning Outcomes: The Concept of Tropism Movement in 7th Grade Junior High School Students by Rina Purwendri, tropism movement is the movement or part of a plant whose direction is influenced by the direction of the stimulus. When viewed from the type of stimulus, tropism movement is divided into phototropism, geotropism, thigmotropism, hydrotropism, and chemotropism. See the explanation of each below:

Phototropic Movement

The stimulus for phototropism is light, for example the tip of a plant moving towards the direction of sunlight.

Geotropism Movement

The stimulus for geotropism is the Earth's gravitational force. For example, the movement of plant roots toward the center of the Earth.

Thigmotropic Movement

The stimulus for geotropism is touch or contact, for example the movement of plant tendrils that twine around stakes, such as cucumbers, betel, passion fruit plants, grapes and watermelons.

Hydrotropism Movement

The stimulus for hydrotropism is water, for example roots moving towards a water source.

Chemotropism Movement

Chemotropic movement has a stimulus in the form of a chemical substance, we can find this in plant roots that move towards fertilizer.

That is a review of plant movements that are influenced by light stimuli. Visit VOI.id to get other interesting information.