Molecular, biophysical, and biochemical studies on irradiated Zea mays seeds using various sources of gamma rays for dosimetrical applications

Gamma rays are a powerful tool for enhancing crop quality and production. They can cause mutations that improve plant traits and are commonly used in agriculture. The present study aimed to examine the effects of gamma irradiation on maize hybrids' triple white seeds (Giza 321) using different doses (10, 20, and 50 Gy) from different radiation sources ⁶⁰Co or ¹³⁷Cs). The maize treated with gamma rays from the Co-60 source at 10 Gy exhibited the lowest shoot length percentage of 37.5%, compared to control groups, while root lengths were unaffected at 10 and 50 Gy Cs-137 doses. In addition, the study revealed that gamma irradiation stimulated the excess production of proline, protein, and antioxidant enzymes, which revealed the defense strategy of the plant that tolerates stress. The study also revealed that gamma rays caused a significant reduction in chlorophyll content for all doses, while carotenoid content increased. DNA tail length indicated that minimal damage occurred at 50 Gy of ⁶⁰Co and ¹³⁷Cs, respectively. Moreover, the analysis of tail DNA% and tail moment showed that the lowest damage was determined for 20 Gy of ⁶⁰Co and ¹³⁷Cs, respectively. SDS-PAGE analysis showed that the 20 Gy Co treatments had the largest number of bands (15), while the 20 Gy Cs dose had the minimum number of bands (10). Ultimately, the proline content and peroxidase enzymes respond exponentially with the dose, making them potential radiation biomarkers for dosimetric purposes. However, further dosimetric features of these two parameters are necessary to be defined in future work. The present results showed that the treatment of plants with gamma rays enhanced the defense system of the maize at a specific dose, thereby, a large-scale study is recommended for using this radiation to enhance the defense and/or the tolerance of a wide range of crops as well as evaluate its safety, applicability, and reproducibility at field scale.