Assessment of protein and DNA polymorphisms in corn (Zea mays) under the effect of non-ionizing electromagnetic radiation

Abstract

Many reports highlight biological responses of crop plants after non-ionizing electromagnetic radiation (EMR) exposure based on the phenotypic and physiological levels. So, this study aimed to estimate genetic alterations in proteins, isozymes, and DNA banding patterns as well as the extent of nuclear DNA damage of economic corn (Zea mays) under the stress of EMR using accurate and reliable bioassays like sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isozymes (Leucine- aminopeptidase, Esterases, Peroxidase, and Catalases), random amplified polymorphic DNA- polymerase chain reaction (RAPD-PCR), and Comet Assay, respectively. SDS-PAGE analysis showed distinct polymorphisms (96.66%) between EMR exposed and non-exposed corn seedlings depending on the number and type of bands, their intensities as well as molecular weight which ranged from (60.27 to 192.35 kDa), gain, and loss of bands. The four isozymes generated varies isozymatic polymorphisms based on relative front, zymogram number, and optical intensities. RAPD analysis generated 85 amplified DNA products with high polymorphism values ranged from 90.91 to 100% based on primers, band type, DNA sizes which ranged from 153 to 1008-bp, lose, gain, and intensity of DNA bands. Comet Assay scored highest extent of loosed DNA from nuclei (DNA damage) reached the value of (tailed ratio 20%) at EMR exposed corn nuclei for 5 days compared to non-exposed nuclei which reached the value of (tailed ratio 3%). This study concluded that each EMR exposure time had unique interaction with proteins, isozymes, and DNA of corn cells exhibiting wide range of genotoxic stress and subsequently, adversely effect on growth and yield of this sensitive crop plants.