Development of the leaf epidermis

This chapter discusses the development of the leaf epidermis. The epidermis is the cell layer that forms the interface between a plant and its environment. As such, the epidermis is crucial for protecting the plant against environmental insults and for regulating the exchange of materials between a plant and its environment. Leaves are the major site of gas exchange, transpiration, and attack by insects and pathogens. The leaf epidermis is of particular importance for plant protection. Plant epidermises have evolved various features to allow the performance of this protective role. The epidermis consists of epidermal ground cells interspersed with specialized structures, such as stomates, trichomes, or fibers, which enable the epidermis to perform its various functions. This chapter provides a broad framework to consider the various aspects of epidermal development. The focus is on angiosperms and particular attention is paid to model systems, where the most information is available. The epidermis is covered by a waterproof layer of complex lipid polymers called the “cuticle.” The cuticle has a layered structure and the surface can be variously textured. The epidermis consists of relatively unspecialized ground cells interspersed with specialized cell types, such as stomates or trichomes. Epidermal characteristics vary from organ to organ or according to position within an organ. The potential role of the epidermis in controlling organ expansion raises the question of whether the epidermis is the target of hormone action. The leaf epidermis provides an attractive system for studying the process of cell differentiation. It is readily accessible and replica techniques allow the sequential viewing of the same cells during development. © 1999 Academic Press Inc.