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A remarkable example of phototropism is seen in sunflowers, which track the sun’s movement across the sky. Young sunflowers exhibit this behavior by elongating one side of their stem during the day and the other side at night, allowing them to follow the sun from east to west. This ability to track sunlight, termed heliotropism, demonstrates the sophisticated mechanisms that plants use to maximize their exposure to light for photosynthesis.
Response to Other Stimuli: Gravity and Mechanical Stimulation
In addition to light, plants respond to gravity to properly orient their growth. Their roots generally grow downwards in response to gravitational pull, while shoots grow upwards. This phenomenon is an essential survival adaptation for plants.