Dictionary > Hydrotropism


Growth or movement response of a cell or an organism to moisture or water
In general, tropism is an orienting response of an organism to a stimulus. It often involves the growth rather than the movement of an organism. The response exhibited by the organism to the stimulus is mostly involuntary, which means it cannot go either towards or away from the stimulus source as in taxis. In tropism, the response of the organism is often by its growth rather than by its movement. It may grow either towards or away from the stimulus.
Hydrotropism is a form of tropism characterized by the growth or movement response of a cell or an organism to moisture or water. The response may be positive or negative. A positive hydrotropism is one in which the organism tends to grow towards moisture whereas a negative hydrotropism is when the organism grows away from it. An example of positive hydrotropism is the growth of plant roots towards higher relative humidity level. The plant is able to sense this at the root cap and then sending signals to the elongating part of the root. Nevertheless, gravitropism often has more influence on root growth than hydrotropism.1
Word origin: Ancient Greek hudro-, húdōr (“water”) + tropism
See also:


1 Takahashi, N., Yamazaki, Y., Kobayashi, A., Higashitani, A., & Takahashi, H. (June 2003). “Hydrotropism interacts with gravitropism by degrading amyloplasts in seedling roots of Arabidopsis and radish”. Plant Physiol. 132 (2): 805–810.

You will also like...

temperature - abiotic factor
Abiotic and Biotic Factors

This tutorial deals with the abiotic factors of the freshwater environment that determine what sort of life would be sui..

DNA carries genes coding for proteins
Genetic Information and Protein Synthesis

Genes are expressed through the process of protein synthesis. This elaborate tutorial provides an in-depth review of the..

Chromosome Mutations
Chromosome Mutations

Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..

An artistic depiction of a human embryo
Growth and Development of a Human Baby

Upon fertilization, a zygote forms and develops into an embryo. This tutorial elaborates on the growth and development f..

Human Nervous System
The Human Nervous System

The nervous system is essentially a biological information highway. This tutorial gives an overview of the nervous syste..

The Human Physiology
The Human Physiology

Physiology is the study of how living organisms function. Thus, human physiology deals specifically with the physiologic..