What Does Hydrotropism Mean?
In plant biology, hydrotropism is a plant’s growth response towards
water sources. Hydrotropism, which is triggered by plant hormones, can be a positive or negative response, whereby
the plant will either turn away from water concentrations, protecting itself from oversaturation, or move towards them, protecting itself in times of drought.
Consequently, through hydrotropism, the plant is able to avoid drought-related stress since the
root cap can orientate itself towards moister parcels of land.
Maximum Yield Explains Hydrotropism
Plant hormones known as auxins play an important role in
bending or orienting the roots towards water sources. These hormones have also
been known to trigger a rapid growth spurt in one side of the root, hence
enabling the plant to bend towards the water.
A plant’s ability to grow towards
some kind of moisture gradient can protect the plant from various kinds of
mineral deficiency. Studies have shown that hydrotropism can allow plants to
grow in space, whereby the roots respond directly to environmental stimulation
in spite of zero gravity. However, it has been noted that hydrotropism in micro
or zero gravity causes the plants to grow sideways or latterly.
Hydrotropism is just one of many ways plants can move in response to their surroundings. Other ways plants move include:
- Gravitropism and geotropism (movement relative to a gravitational field, or toward the center of the Earth)
- Thigmotropism (plant growth in response to physical contact)
- Chemotropism (movement in response to a chemical in the environment)
- Phototropism (plant growth and movement in response to lighting levels)
- Thermotropism (response dependent upon temperature)
Plant movement, including hydrotropism, has been fascinating researchers for decades.