Seed Gamma Irradiation of Arabidopsis thaliana ABA-Mutant Lines Alters Germination and Does Not Inhibit the Photosynthetic Efficiency of Juvenile Plants

Abstract

Plant growth response to γ-irradiation includes stimulating or inhibitory effects depending on plant species, dose applied, stage of ontogeny and other factors. Previous studies showed that responses to irradiation could depend on ABA accumulation and signaling. To elucidate the role of ABA in growth and photosynthetic responses to irradiation, lines Col-8, abi3-8 and aba3 -1 of Arabidopsis thaliana were used. Seeds were γ-irradiated using 60Co in the dose range 50-150 Gy. It was revealed that the dose of 150 Gy affected germination parameters of aba3 -1 and Col-8 lines, while abi3-8 line was the most resistant to the studied doses and even showed faster germination at early hours after γ-irradiation at 50 Gy. These results suggest that susceptibility to ABA is probably more important for growth response to γ-irradiation than ABA synthesis. The photosynthetic functioning of 16-day-old plants mainly was not disturbed by γ-irradiation of seeds, and no indication of photosystem II photoinhibition was noticed, revealing the robustness of the photosynthetic system of A. thaliana. Glutathione peroxidase activity and ABA concentrations in plant tissues were not affected in the studied dose range. These results contribute to the understanding of germination and photosynthesis fine-tuning and of mechanisms of plant tolerance to ionizing radiation.

Enhancement Rutin Production from Capparis spinosa Plant by UV-C or Gamma Irradiation using In vitro Culture

“…b. Exposure to gamma rays with three concentrations (0.5, 1, 1.5 Gray), was performed at the National Centre for Research and Technology in Nasr City, Cairo, Egypt, using 60^Co-γ of India gamma cell at dose rate (0.782 Gy/h) (Bahmani et al, 2016;Babina et al, 2020).…”

Ionizing Radiation: Effective Physical Agents for Economic Crop Seed Priming and the Underlying Physiological Mechanisms

“…Similar to other types of ionizing irradiation, the stimulatory or inhibitory effects on the plant’s growth depend on the seed species and status, the dose and dose rate, as well as exposure time. In general, the hormesis effect occurs during low-dose irradiation, while on the contrary, the inhibitory effect occurs at higher doses because of the over-produced free radicals damaging the physiological and biochemical properties of the plants [ 70 , 105 , 106 , 107 ]. According to the research, γ-ray radiation, as a high-energy type of IR, can penetrate the cell membranes and interact with tissues, producing ROS by ionizing the water molecules.…”

“…Biotic stresses such as viral or fungal infections, or abiotic stress such as irradiation, salinity, heat, and cold always accelerates inner abscisic acid (ABA) accumulation in plants [ 107 , 114 ]. As it supposed that this technology will alleviate the stress effects of the plants, it has been perceived that γ-ray irradiation could accumulate abscisic acid (ABA) by upregulating the related genes, and such a generation of plant hormones would lead to the synthesis of ROS, and in return, the antioxidant enzyme system would be enhanced by the over-production of ROS which would maintain the optimal redox status in the plants.…”