Determining the Contribution of Epidermal Cell Shape to Petal Wettability Using Isogenic Antirrhinum Lines

The petal epidermis acts not only as a barrier to the outside world but also as a point of interaction between the flower and
potential pollinators. The presence of conical petal epidermal cells has previously been shown to influence the
attractiveness of the flower to pollinating insects. Using Antirrhinum isogenic lines differing only in the presence of a single
epidermal structure, conical cells, we were able to investigate how the structure of the epidermis influences petal
wettability by measuring the surface contact angle of water drops. Conical cells have a significant impact on how water is
retained on the flower surface, which may have indirect consequences for pollinator behaviour. We discuss how the petal
epidermis is a highly multifunctional one and how a battery of methods, including the use of isogenic lines, is required to
untangle the impacts of specific epidermal properties in an ecological context.