Effects of gamma radiation on crop production

Abstract

The increasing world population has raised concerns over food security. In order to feed the world, the projected target is to double food production by 2050. However, this objective has been interrupted by many global challenges, including climatic change and a reduced ozone layer. The Earth is protected by layers of atmosphere. The stratospheric ozone protects living organisms from harmful radiation. Plants use sunlight for photosynthesis and as a consequence face harmful radiation. Depletion of stratospheric ozone has increased radiation entering the surface of the Earth. Radiation is divided into two types: ionizing radiation, where gamma rays are most prominent; and nonionizing radiation, including UV rays. UV rays (high energetic radiation) cause heritable mutations in the genome of plants that exacerbate plant physiology, environmental factors, plant growth, and affect photosystem and soil properties which ultimately affect crop productivity, leading to the incidence and progress of crop diseases. However, plants have evolved methods to reverse the genetic changes by UV radiation by delaying growth and cell division that helps in DNA repair. There have been further studies on plant responses, including in DNA repair enzymes, endogenous photodamaging molecules, and repair machinery towards UV radiations in crop plants. Gamma radiation is high-frequency rays consisting of high-energy protons that penetrate the cell and cause ionization. Ionization of plant cells causes disruption of the normal processes of the cell ultimately affecting crop yield. Gamma rays are dose dependent, where a low dose has fewer side effects in contrast to a high dose that affects plant phenotype, including various cell organelles and biochemical components. However, there are several biochemical parameters to identify the damage caused by this radiation. Nevertheless, the plant defense mechanism is activated under a low dose of gamma rays to cope with the damage. Gamma rays also have various benefits in all applied fields and are used to create crop mutants. This chapter discusses the effects of radiation, predominantly UV and gamma rays in crops and their benefits.