What does thermotropism mean?
Thermotropism is the directional growth of a plant in response to differences in temperature. It is commonly described as positive or negative: positive thermotropism occurs when growth is directed toward a warmer area, while negative thermotropism occurs when growth is directed away from it. The process is distinct from the more familiar phototropism, in which plants bend toward light, because the relevant stimulus here is temperature rather than light. Thermotropism is mainly a botanical term, used in discussions of plant physiology, agriculture, and environmental responses, although related temperature-directed movements may be studied in other organisms under the separate concept of thermotaxis. Understanding thermotropism helps explain how plants adjust their development to uneven thermal conditions, such as a warm edge of a greenhouse or a cold patch of soil. The word is useful whenever precise terminology is needed to distinguish growth direction caused by heat from other plant responses.
nounThermotropism is the directional growth response of a plant to a difference in temperature, with growth oriented toward or away from a warmer region.
- The directional growth of a plant in response to a temperature gradient.
"The seedling exhibited positive thermotropism, bending its growth toward the warmer side of the greenhouse."
"The seedling exhibited positive thermotropism, bending toward the warmer side of the greenhouse."
"Researchers studied thermotropism by changing the temperature across a growing shoot."
Usually singular when referring to the general process, but plural can be used for multiple distinct instances or examples.
"The researchers compared thermotropisms in several species under controlled temperature conditions."
Thermotropism lets plants use temperature as a compass, turning their growth toward warmth or away from it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thermotropism come from?
Thermotropism is formed from the Greek thermos, meaning “heat,” and tropism, a term associated with Greek trope, meaning “turning” or “direction.” The compound belongs to the vocabulary of botanical growth responses. Related words such as phototropism and geotropism follow the same structure, using thermo-, photo-, and geo- to identify the stimulus that determines the direction of growth.
Related word forms
How thermotropism is actually used
This is a specialized biological term, used most often in botany and plant physiology. It normally describes growth rather than movement, so it should not be confused with thermotaxis.
Easily confused with thermotropism
Thermotropism is a growth response to temperature, whereas thermotaxis is movement toward or away from a temperature stimulus.