Negative tropism, or tropotropism, is a type of plant growth response in which a plant bends away from a stimulus. The term is derived from the Greek words tropos (“a turning”) and tropos (“a turning”) (Bologna, 2019). It is the opposite of positive tropism, which is a plant response in which the plant bends towards a stimulus. Negative tropism can be observed in many plant species, including grasses, herbs, and trees.
Tropism is a type of plant growth response that is triggered by environmental stimuli such as light, gravity, temperature, and touch. Plants use tropism to orient themselves towards or away from a stimulus, thus allowing them to better adapt to their environment (Chong et al., 2016). For example, plants may use negative tropism to move away from areas with intense light or heat, or to move away from areas with unfavorable soil conditions.
Negative tropism is usually triggered by touch or gravity, though it can be triggered by other environmental stimuli as well. Touch-induced negative tropism is called thigmotropism, and it occurs when a plant’s stem grows away from the source of touch. Gravity-induced negative tropism is called geotropism, and it occurs when a plant’s roots grow away from the source of gravity (Chong et al., 2016).
Negative tropism is an important factor in plant growth and survival, as it allows plants to avoid unfavorable conditions and to optimize their growth and development. For example, when plants sense that the soil in a certain area is too dry or too wet, they may use negative tropism to grow away from that area (Chong et al., 2016). This helps the plant to survive in a variety of environmental conditions, as it allows the plant to avoid areas that may be detrimental to its growth.
In conclusion, negative tropism is an important type of plant growth response that allows plants to better adapt to their environment. Negative tropism can be triggered by touch, gravity, light, and other environmental stimuli, and it helps plants to avoid unfavorable conditions and optimize their growth.
References
Bologna, M. (2019). Plant Tropism. Encyclopedia Britannica. https://www.britannica.com/science/plant-tropism
Chong, C. K., Faria, J. P., & Giddings, T. (2016). Plant tropism. Molecular Plant, 9(6), 797-813. doi:10.1016/j.molp.2016.03.001