Statoliths

Definition

Statoliths are specialized organelles in plant cells that assist in gravity perception. They are dense, starch-filled plastids found in root cap cells and other tissues involved in gravitropism.

5 Must Know Facts For Your Next Test

1. Statoliths settle at the lowest part of the cell, helping plants detect the direction of gravity.
2. They are primarily composed of starch, which makes them denser than the surrounding cytoplasm.
3. The movement and position of statoliths trigger signaling pathways that direct root and shoot growth.
4. Statoliths can be found in both roots and shoots but are most commonly studied in root cap cells.
5. The redistribution of auxin, a plant hormone, is influenced by the position of statoliths, affecting differential growth.

Review Questions

• What role do statoliths play in plant cells?
• How do statoliths contribute to a plant's ability to sense gravity?
• Where within a plant cell are statoliths typically located?

Related terms

Gravitropism: The orientation or growth of a plant in response to gravity.

Auxin: A class of plant hormones that regulate various aspects of growth and development, including gravitropic responses.

Root Cap: A structure at the tip of a root that protects it as it grows through the soil and contains cells with statoliths for gravity sensing.