ABSTRACT
UV radiation like several other abiotic stresses (heat, drought, ionizing radiation, chill, water, etc.) causes a spike in reactive oxygen species (ROS) content and other secondary metabolites (stress enzymes, flavonoids, phenolics, chlorophyll derivatives, essential oils, other pigments, etc.) in the field, experimental as well as in post-harvest treatment. These have the potential to damage DNA, proteins, lipids, phytochromes, molecules containing conjugated double bonds, pigments systems such as PSI and PSII and ultrastructure of membranes, plastids, mitochondria, etc. UV-A (315–400 nm) and a small portion of UV-B (280–315 nm) reach the earth’s surface and most of the plants are adapted to resist or absorb this much of UVR. Increasing UV radiation due to thinning of atmospheric ozone layer and applications of UV treatment for harvest protection causes degradation of chlorophyll content, less productivity, kernel damage, discoloration of fruits, the morphology of leafy vegetables, food quality and taste, food security, and in an overall economic loss. UVR synergistically aggravates with other physical and chemical stress, weakens plants defense mechanisms toward pathogens, and results in necrosis, mutation, and formation of unwanted phytochemicals in later stages of growth and post-harvest. Application of selective usage of UV dose in the later stage of production, post-harvest sanitization, and freshly cut and packed vegetables may prove better food security and post-harvest loss.
