Hypocotyl

Hypocotyl

The Hypocotyl is a significant part of the embryo in a seed of a dicot and some monocot plants. It is the stem of a germinating seedling, found below the cotyledons (seed leaves) and above the radicle (root).

Structure and Function

The hypocotyl is the primary region of a young plant's stem. It develops from the plumule, which is the embryonic shoot within the seed. The hypocotyl is the transitional area between the root and the stem, and its primary function is to raise the cotyledons above the ground surface following germination.

In some plants, the hypocotyl becomes elongated as a part of germination. This pushes the cotyledons above the soil surface, where they can receive sunlight for photosynthesis. In other plants, the hypocotyl remains short, and the cotyledons stay below the ground surface.

Hypocotyl Development

The development of the hypocotyl is a critical stage in a plant's life cycle. It begins with the germination of the seed, which is triggered by the presence of water, suitable temperature, and in some cases, light. The hypocotyl is the first part of the plant to emerge from the seed during germination.

The length of the hypocotyl can vary greatly among different species and even among different varieties of the same species. This variation is due to both genetic factors and environmental conditions, including light and temperature.

Hypocotyl in Plant Research

The hypocotyl is often used in plant research because it is easy to manipulate and observe. It is commonly used in studies of plant growth and development, including research on plant hormones, phototropism, and gravitropism.

See Also

• Cotyledon
• Radicle
• Plumule
• Germination
• Phototropism
• Gravitropism