Pericycle Cells (Side Root Starters)

Just inside the gatekeepers

In the center of a root are the plant's water and sugar pipes. Around them is a ring of gatekeeper cells called the endodermis.

Just inside the endodermis, wrapped right around the pipes, is a thin layer of cells called the pericycle. Pericycle cells are alive and can start dividing again when the plant needs them.

Starting new side roots

When a root needs to branch, a few pericycle cells start to divide:

• They make a small bump of new cells.
• The bump grows into a new root tip.
• It pushes out through the endodermis, the cortex, and the root's skin into the soil.

In roots that grow thicker, like tree roots, pericycle cells also help start the layers that make new wood and bark.

Pericycle quiz