PRODUCTION OF AUXINS AND THEIR EFFECTS ON PLANT GROWTH.
Auxins are produced by plant apices, i.e. root apex and shoot apex.
They bring about cell elongation resulting in growth.
They are diffusible substances which effect growth when in very small amounts.
Roots require lower concentrations than shoots.
The effect of auxins on the growth of roots and shoots has already been discussed.
Auxins also exert other effects on plant growth and development.
There are various other chemical substances which have been shown to influence plant growth and development.