Chapter 20 - Fleshy Fruit Epidermis is a Protective Barrier Under Water Stress

Abstract

Fruits may be exposed to several unfavorable mechanical, climatic, and biological factors during ripening. Harvest and storage also challenge fruit integrity before fruits reach the consumer. In order to preserve fruit properties/characteristics it is essential that the structural and chemical integrity of the cuticle is maintained throughout fruit development and expansion. In addition, cuticles serve as protection against multiple biotic and abiotic stress factors and primarily act as a barrier to prevent water loss. Despite the important functions attributed to the cuticle, little is known about fruit cuticle biosynthesis and assembly, which is highly relevant when coping with adverse conditions. Presently, drought and heat pose severe constraints to the fruit industry via penalties in yield and fruit quality. Available climate change models suggest a scenario in which the impact of these environmental factors will negatively affect the fruit industry. A comprehensive understanding of the physiological and biochemical effects of limited water availability on fruit traits is a prerequisite for implementing breeding and knowledge-based strategies that enhance fruit crop tolerance to limited water availability. To address some of these questions, this chapter aimed to revise the existing information on cuticle physiology, composition, structure, and properties, also considering its impact on fruit under abiotic stresses, with an emphasis on water deficit. We also address the recent molecular progress in cuticle biosynthesis pathways and highlight some of the major research questions that will have to be dealt with in the future.