ABSTRACT
In this chapter, the authors describe a model for the export of floral scent compounds, and compares the few available literature data, and explains the various open questions in this field. Their model will use chemical, physiological, morphological, biochemical, and molecular arguments to describe the export of volatiles from floral scent-producing cells. Four major steps are likely to be involved in floral volatile emission: trafficking within the epidermal cell, export from the plasma membrane into the epidermal apoplast and subsequent transport across the cell wall, permeation of the cuticle, and evaporation at the surface of the cuticle. Scent-producing floral organs have epidermis cells with pronounced conical shapes. The conical shape of the epidermal cells obviously increases the scent-emitting surface of the cells when compared with flat epidermal cells typical for vegetative organs. One frequently stated interpretation is that the structures facilitate emission of scent molecules by increasing the surface area of the epidermal cells.
