Stimuli and responses in plants

• Plants respond to touch, water, light, and gravity which are divided into two, namely the tropism response and the nastic response.
• Types of tropism and reactions include phototropism, geotropism, hydrotropism, and thigmotropism.
• Phototropism is the growth of plant parts towards the light, such as the growth of sunflower shoots in the direction of sunlight.
• Geotropism is the growth of plant parts towards gravity, such as root growth of red chili trees according to the direction of gravity.
• Hydrotropism is the growth of plant parts towards the water, such as the growth of pandan tree roots in the direction of water.
• Thigmotropism is the movement of plant growth against touch or when in contact with an object, such as cucumbers having suckers that twist an object that touches them.
• Nastic response is the response of plants to touch, light, and heat, where the direction of the response does not depend on the direction of the stimulus
• Phototropism helps shoots get sunlight for photosynthesis.
• Geotropism helps the roots penetrate the soil to obtain water and the roots can grip the soil firmly.
• Hydrotropism helps plant roots absorb water and mineral salts from the soil.
• Thigmotropism helps plants reach the highest position to get sunlight and maintain an upright position.
• Nastic movement protects leaves from injury.