Chemotropism is the growth response to a particular substance.
Tropism is a growth response in all or part of a plant due to an external stimulus. Chemotropism in particular is in response to a particular substance (chemo-) and may be further divided as negative or positive chemotropism.
Negative chemotropism will cause the plant to move away from the substance, while positive chemotropism will cause the plant to move towards the substance.
Chemotropism is known to be valuable for plants in reproduction. For example, when angiosperm plants are pollenated, the pollen is received and begins to produce a pollen tube. The growth of that tube is directed by the chemicals secreted by the ovule. This pollen tube then allows fertilization to take place when it reaches the ovule.« Back to Glossary Index