A- Auxins initiate and promote cell division in cambium.
B- Low level of auxin in plant body will lead to premature falling of leaves, fruits and flowers.
 

Auxin is responsible for initiation and promotion of cell division in cambium. This effect of auxin is particularly important in secondary growth of stem and differentiation of xylem and phloem tissues. Auxins help to prevent fruit and leaf drop at early stages but promote the abscission of older mature leaves and fruits.