Elicitation-Based Modulation of Shelf Life in Fruits: Physiological and Molecular Insights

Abstract

The process of ripening involves physiological and biochemical events that become a concern during postharvest storage. We have documented different approaches for the preservation and maintenance of fruit quality during the postharvest period that are biocompatible and fully safe for consumption. Chemical residues that sustain sensory characteristics, such as color, flavor, aroma, and texture, are considered. In fruit ripening, both physical and chemical elicitors are described that regulate ethylene biosynthesis or its signaling for gene expression. The key regulatory enzymes, such as ACC synthase and ACC oxidase, for ethylene biosynthesis, are important for both climacteric and non-climacteric fruits. Anti-oxidizing genes that retain sensory characteristics are concerns in this respect. Chemical elicitors, including chitosan, polyamine, phenolics, lipopolysaccharide, silver derivatives, and nanocomposites, are described. Gas pressure, light wavelengths, relative humidity, cooling, and other environmental factors are important for improved postharvest storage. These elicitors maintain redox status by inhibiting the generation of reactive oxygen species (ROS) or their lysis. Growth regulators, including abscisic acid, auxin, brassinosteroids, jasmonic acid, and salicylic acid, are important for the regulation of ripening. Mechanical inju-ries, ionic imbalances, temperature variations, and tissue dehydration can occur irrespective of ripening cate-gories. The use of synthetic physiochemically active compounds is discussed in terms of physiological, metabolic, cellular, and molecular functions. Ethylene-induced autocatalytic processes, antioxidant cascades, epi-genetic regulation, and homeodomain gene expression are discussed. Sugar–acid metabolism, dissolution of the cell wall, and direct or indirect production of secondary metabolites related to postharvest storage are mentioned regarding chilling storage. Elicitors and agrochemicals that trigger plant defense to increase secondary metabolite production are discussed for reducing fruit senescence during postharvest storage.