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

Abstract

To overcome various factors that limit crop production and to meet the growing demand for food by the increasing world population. Seed priming technology has been proposed, and it is considered to be a promising strategy for agricultural sciences and food technology. This technology helps to curtail the germination time, increase the seed vigor, improve the seedling establishment, and enhance the stress tolerance, all of which are conducive to improving the crop yield. Meanwhile, it can be used to reduce seed infection for better physiological or phytosanitary quality. Compared to conventional methods, such as the use of water or chemical-based agents, X-rays, gamma rays, electron beams, proton beams, and heavy ion beams have emerged as promising physics strategies for seed priming as they are time-saving, more effective, environmentally friendly, and there is a greater certainty for yield improvement. Ionizing radiation (IR) has certain biological advantages over other seed priming methods since it generates charged ions while penetrating through the target organisms, and it has enough energy to cause biological effects. However, before the wide utilization of ionizing priming methods in agriculture, extensive research is needed to explore their effects on seed priming and to focus on the underlying mechanism of them. Overall, this review aims to highlight the current understanding of ionizing priming methods and their applicability for promoting agroecological resilience and meeting the challenges of food crises nowadays.

Comparative Analysis of the Effect of Gamma-, Electron, and Proton Irradiation on Transcriptomic Profile of Hordeum vulgare L. Seedlings: In Search for Molecular Contributors to Abiotic Stress Resilience

“…Ionising radiation, including γ-radiation, electrons, and protons, converts neutral atoms or molecules into reactive ions, triggering various biological effects and targeting plant signalling systems [43,44]. The IR types studied here can be considered as low linear energy transfer radiation, with relative biological effectiveness close to 1.…”

Cytogenetic and Biochemical Responses of Wheat Seeds to Proton Irradiation at the Bragg Peak

“…[ 56 , 57 ]. These radicals are toxic for a wide range of biological macromolecules such as DNA, lipids, and proteins [ 20 , 58 ]. Among these radiolysis products, the hydroxyl radical is the most dangerous for living tissues because of its high reactivity [ 59 , 60 ].…”

“…The link between the appropriate irradiation dose and mutation frequency is useful to minimize other harmful effects on plant survival and reproduction, although there is no analysis to support the relationship between irradiation dose and mutation frequency [ 19 ]. Physical strategies (such as ionizing radiation: X-rays, gamma rays, electron beams, proton beams, and heavy ion beams) used for seed priming are promising compared to traditional methods because they are time-saving, more efficient, more environmentally friendly, and there is greater certainty to improve yield in contrast to conventional methods (use of water or different chemicals) [ 20 ].…”

“…Proton particle radiation is a major part of solar particle events (about 87%) and consists of protons (hydrogen nuclei) with a certain energy (1~1000 MeV) which can stimulates organisms in a non-thermal manner [ 20 ]. Protons are usually absorbed by the plant and cause various changes in the physiological (stimulates the absorption of water by the seeds and photosynthetic pigments) and biochemical parameters (increase in the level of ROS, antioxidants) and the development of the plant’s defense systems to strengthen the production of culture [ 21 , 22 , 23 , 24 ].…”

Use of Low-dose Gamma Radiation to Promote the Germination and Early Development in Seeds

“…The vast majority of plant foods are produced by crops that are propagated by seeds, but the germination process is highly vulnerable to external conditions, which can cause delayed and/or uneven germination or even weak seedlings, which will inevitably end up affecting the yield and production quality [4]. In search of alternatives to reduce the difficulties associated with seed quality, low doses of IR have begun to be applied to speed up the Seed Biology -New Advances germination processes, increase seedling quality, and to improve tolerance to biotic and abiotic stressors [5].…”