Auxins are a type of plant hormone that play a crucial role in growth and development. They are primarily produced in the apical regions of both roots and shoots. These regions are responsible for the growth of the plant, so the production of auxins in these areas allows for the regulation of growth and development throughout the plant. While auxins can also be found in other parts of the plant such as the parenchyma of roots and shoots, and the epidermis of roots and shoots, their primary site of production is in the apical regions.