The primary root, or the root that is initiated in the embryo within the seed, is the original root of a plant to discover its soil environment. It is essential for the anchoring of the plant and ensures plant growth through the uptake of water and nutrients. In this review, we describe the tissue organisation of the primary root, not only largely focusing on the model species
Arabidopsis thaliana
but also mentioning some other plant species where relevant. We also flag, non‐comprehensively, some of the molecular factors important for proper root formation and growth, plant growth regulators or hormones that determine primary root growth as well as interactions with the environment that shape the root system and refer to relevant literature for further detailed information.
Key Concepts
The primary root is initiated in the embryo within the seed.
The primary root is only a (small) part of the complex root system architecture.
The primary root is an ideal model system to study cell division, differentiation and identity.
There are complex and tightly regulated molecular patterning events to ensure proper primary root tissue organisation and a lot of these regulations involve plant hormones.
The primary root is a dynamic interface with the soil environment.