NADPH as a quality footprinting in horticultural crops marketability

Background: During their post-harvest life, horticultural crops are affected by a diverse range of processes, such as natural in planta senescence and fungal infection, as well as artificial conservation techniques, leading to a deterioration in nutritional quality due to chilling damage. Given its intracellular reducing power, the supply of NADPH needs to be optimized in order to maintain multiple metabolic pathways involved in the natural ripening and post-harvest life of horticultural crops. Scope and approach: As a whole series of reactions are involved in the generation and functioning of the cellular NADPH pool, the homeostasis of NADPH integrates and coordinates different metabolic pathways involved in physiological processes. In this review, we describe the major pathways in NADPH metabolism which modulate the principal enzymes present in subcellular compartments that generate and consume NADPH. Special attention will be paid to its role in fruits and vegetables and its possible use as an indicator of horticultural crop quality. In addition to playing a key role in cellular redox status, NADPH could also be used as a footprint of horticultural crop quality for marketing purposes given its involvement in processes such as photosynthesis, carbohydrate activity, reactive oxygen species (ROS) and fatty acid metabolisms, the pentose phosphate pathway, jasmonic acid biosynthesis, as well as shikimate and phenylpropanoid pathways operating in secondary metabolite biosynthesis. Key findings and conclusions: Intracellular NADPH metabolism could provide a physiological, biochemical and molecular footprint for the sensory and nutritional quality of post-harvest horticultural crops and their marketing worldwide.