epicutícula

Epicuticle is the outermost layer of the cuticle in terrestrial plants and some algae. It is a thin, waxy coating that covers the epidermis of aerial plant parts, such as leaves and stems. The epicuticle is primarily composed of cutin, a complex polyester of fatty acids, and can also contain waxes. Its main function is to reduce water loss from the plant surface, a crucial adaptation for life on land where dehydration is a constant threat.

Beyond preventing desiccation, the epicuticle plays a role in protecting the plant from various environmental stresses. It acts as a barrier against UV radiation, pathogen invasion, and insect herbivory. The thickness and composition of the epicuticle can vary significantly among different plant species and even within different parts of the same plant, reflecting adaptations to specific ecological conditions. For example, plants in arid environments often have a thicker, more impermeable epicuticle to conserve water.

The formation of the epicuticle occurs during the development of epidermal cells. Specialized proteins and enzymes are involved in synthesizing and depositing cutin and waxes onto the outer cell wall. The structure of the epicuticle is not uniform; it can exhibit variations in its continuity and the presence of pores or channels, which may influence gas exchange and the absorption of certain external substances. Despite its thinness, the epicuticle is vital for plant survival and resilience.