Plant Cuticle Synthesis and Tolerance to Stress

The plant cuticle is a crucial protective barrier at the interphase between the plant and the environment that covers the whole aerial part of plants. Cutin is the main component of the cuticle matrix, which also contains waxes, polysaccharides, phenols, and other minor components. The plant cuticle originated early during land plant colonization. The loss of water is considered the primary driven force for its appearance and evolution in the transition from aquatic to terrestrial habitats, approximately 460 million years ago. Currently, the plant cuticle not only is viewed as a modification of the outer epidermal cell wall that acts as an impermeable barrier to minimize water loss from the plant but also has a relevant role in the mitigation of gas exchange and temperature shifts and in the protection from solar radiation and pathogen attack. Due to its relevance in plant development and commercial issues, particularly in relation to fruit cracking, the studies of plant cuticles have gained significant attention. Its molecular composition and biophysical properties have been reported in a few plant models. To date, several transcription factor families and genes encoding metabolic pathways enzymes are known to be involved in cuticle development and properties. This chapter will revise the current knowledge on plant cuticle synthesis with emphasis on the role of cuticle compounds and key genes in plant tolerance to different abiotic and biotic stressors.