Auxins

Nature of Auxins:

The term auxin is derived from the Greek word auxein which means to grow. Compounds are generally considered auxins if they can be characterized by their ability to induce cell elongation in stems and otherwise resemble indoleacetic acid (the first auxin isolated) in physiological activity. Auxins usually affect other processes in addition to cell elongation of stem cells but this characteristic is considered critical of all auxins and thus "helps" define the hormone (Arteca, 1996; Mauseth, 1991; Raven, 1992; Salisbury and Ross, 1992).

Functions of Auxin:

The following are some of the responses that auxin is known to cause (Davies, 1995; Mauseth, 1991; Raven, 1992; Salisbury and Ross, 1992).
Stimulates cell elongation
Stimulates cell division in the cambium and, in combination with cytokinins in tissue culture
Stimulates differentiation of phloem and xylem
Stimulates root initiation on stem cuttings and lateral root development in tissue culture
Mediates the tropistic response of bending in response to gravity and light
The auxin supply from the apical bud suppresses growth of lateral buds
Delays leaf senescence
Can inhibit or promote (via ethylene stimulation) leaf and fruit abscission
Can induce fruit setting and growth in some plants
Involved in assimilate movement toward auxin possibly by an effect on phloem transport
Delays fruit ripening
Promotes flowering in Bromeliads
Stimulates growth of flower parts
Promotes (via ethylene production) femaleness in dioecious flowers
Stimulates the production of ethylene at high concentrations

Above describes the effect of auxin on strawberry development. The achenes produce auxin. When removed the strawberry does not develop (Raven, 1992).

source:

http://www.plant-hormones.info/auxins.htm