Do Roots Have Stomata?
No, roots typically do not have stomata. Stomata are specialized pores found primarily on leaves and stems of plants. They regulate gas exchange (carbon dioxide and oxygen) and transpiration (water loss). Roots, being underground, do not require these structures for gas exchange, as they obtain oxygen from air pockets in the soil.
- Subterranean Environment: Roots are located underground, where the air is not freely available. The exchange of gases like carbon dioxide and oxygen happens through diffusion from the soil pores. Stomata, which are designed for gas exchange in atmospheric conditions, are not necessary. (Quora)
- Alternative Gas Exchange: Roots absorb oxygen directly from the air spaces within the soil. (RHS Gardening)
Exceptions: A Rare Occurrence
While rare, there are exceptions. Some studies have reported the presence of stomata-like structures on the primary roots of certain plants during embryogenesis, before seed desiccation. For example, the Ceratonia siliqua L. (carob tree) has been shown to possess stomata on its primary root. (PubMed, PMC) These stomata may play a role in gas exchange during early development or nutrient transfer. However, this is not the norm.
The presence of these structures on roots doesn't change the fundamental fact that the vast majority of roots do not possess functional stomata in the same way leaves do.
In Summary
Although some exceptional cases exist, roots generally lack stomata. Their function in gas exchange and water regulation is fulfilled by other means adapted to the underground environment.
