Primary and secondary functions of plant roots post briefly explains about primary and secondary functions of roots.
Primary functions of roots
2. Absorption of Water
3. Prevent Soil Erosion
To avoid soil erosion, roots securely retain soil particles in place.
Secondary functions of roots
It occurs in fleshy roots. Examples of fleshy tap roots are: (i) Conical, e.g., Carrot, (ii) Fusiform, e.g., Radish, (iii) Napiform, e.g., Beet, Turnip and (iv) Tuberous, e.g., Mirabilis.
2. Mechanical Support
It is provided by several types of roots: (i) Buttress roots (plank roots), e.g., Bombax, (ii) Prop roots, e.g., Banyan, Rhizophora and (iii) Stilt roots, e.g., Maize, Sugarcane, Pandanus.
Some weak-stemmed plants, such as ivy, tecoma, betel, and money plant, rely on their roots to adhere to a support and therefore climb it.
In many biennial and perennial plants e.g., Trichosanthes.
5. Nitrogen Fixation
Nodulated roots of Pea, Bean, Gram, Methi, etc.
Prop roots, knee roots and pneumatophores of Mangrove plants, e.g., Rhizophora, Heritiera, Sonneratia.
By bearing adventitious buds on both tap roots (e.g., Dalbergia) and adventitious roots (e.g., Sweet Potato).
8. Hygroscopic Roots
The roots absorb water from air, e.g., epiphytic roots, young prop roots of Banyan.
By storing air (e.g., Jussiaea = Ludwigia) some of the roots function as floats.
Lemna, Pistia, and Eichhornia, for example, have a cluster of adventitious roots growing from their nodes and bases to help balance the plants over the water surface.
As in Trapa, Taeniophyllum, Tinospora, Podostemum.
They occur in some parasitic plants for absorption of food from the host, e.g., Cuscuta, Mistletoe.
The roots of several plants are associated with fungi to form mycorrhiza. Mycorrhiza helps the plant in absorption of phosphorus and nitrogen from organic sources and protects the plants from attack of pathogenic fungi.
14. Growth Regulators
Roots synthesize certain growth regulations like cytokinins.