BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Auxin is known to exert an inhibitory role on primary root growth. An auxin gradient, established by local auxin biosynthesis and transport, is important for primary root growth. Auxin synthesized in roots via the IPyA pathway is crucial in normal root elongation and root gravitropic responses [43].

Detailed explanation-2: -Phosphorus (P) and potassium (K) are the two main nutrients that stimulate root growth. Organic fertilisers often display the relative quantities of each, as well as nitrogen (N), in the form of the NPK ratio. In particular, phosphorus allows new root systems to spread through the soil or another growing medium.

Detailed explanation-3: -In horticulture, auxins, especially NAA and IBA, are commonly applied to stimulate root initiation when rooting cuttings of plants.

Detailed explanation-4: -The plant hormone auxin is well known to stimulate cell elongation via increasing wall extensibility. Auxin participates in the regulation of cell wall properties by inducing wall loosening. Here, we review what is known on cell wall property regulation by auxin.

Detailed explanation-5: -Different concentrations of IAA appear to have differing effects on root growth. These effects may vary from one species to another but generally at low concentrations IAA stimulates root growth while at higher concentrations it inhibits root growth.