In
botany
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
, the radicle is the first part of a
seedling
A seedling is a young sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle (embryonic root), the hypocotyl (embryo ...
(a growing plant
embryo) to emerge from the
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
during the process of
germination.
The radicle is the embryonic
root of the plant, and grows downward in the soil (the shoot emerges from the
plumule). Above the radicle is the embryonic
stem or
hypocotyl, supporting the
cotyledon
A cotyledon (; ; ; , gen. (), ) is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The num ...
(s).
It is the embryonic root inside the seed. It is the first thing to emerge from a seed and down into the ground to allow the seed to suck up water and send out its leaves so that it can start photosynthesizing.
The radicle emerges from a seed through the
micropyle. Radicles in seedlings are classified into two main types. Those pointing away from the seed coat scar or
hilum are classified as ''antitropous'', and those pointing towards the hilum are ''syntropous''.
If the radicle begins to decay, the seedling undergoes pre-emergence
damping off
Damping off (or damping-off) is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions.
Symptoms
There ar ...
. This disease appears on the radicle as darkened spots. Eventually, it causes death of the seedling.
The plumule is the baby shoot. It grows after the radicle.
In 1880
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...
published a book about plants he had studied,
The Power of Movement in Plants, where he mentions the radicle.
See also
*
Plant perception (physiology)
Plant perception is the ability of plants to sense and respond to the environment by adjusting their morphology and physiology. Botanical research has revealed that plants are capable of reacting to a broad range of stimuli, including chemic ...
References
{{reflist
Plant anatomy
Plant morphology
Plant cognition