Effect of gamma irradiation on the uptake, translocation, and phytotoxicity of lead and cadmium in a soil–barley (Hordeum vulgare L.) system

Aims This study investigated how gamma irradiation affects the plant growth and the migration of cadmium (Cd) and lead (Pb) within the soil-barley system. Results Our results demonstrated that gamma irradiation increased root length and root-shoot ratio compared with 0 Gy, as well as increased spike length, spikelet number, and spikelet grain weight. Furthermore, 50–150 Gy gamma radiation decreased Cd and Pb contents in grains compared to 0 Gy, Moreover, gamma radiation increased root bioconcentration factor for Cd and Pb (R-BCF Cd and R-BCF Pb, except for 120 Gy in Cd), while the BCF Cd of the barley stem, leaf, and grain all decreased (except for 35 Gy in the leaf), Meanwhile, all gamma radiation treatments decreased translocation factor values from root to stem-leaf for Cd and Pb (R-S+L-TF Cd and R-S+L-TF Pb ) at maturity, with a differential response observed in translocation factor values from stem-leaf to grain for Cd (S+L-G-TF Cd ). In addition, Pearson correlation analysis showed that the variability of Cd content in the grain was significantly and positively correlated with stem BCF Cd (S-BCF Cd ), grain BCF Cd (G-BCF Cd ), and R-S+L-TF Cd . Pb content in the grain was significantly and positively correlated with grain BCF Pb (G-BCF Pb ) and stem-leaf to grain for Pb (S+L-G-TF Pb ). Conclusion Our results suggest 50–150 Gy irradiation reduces heavy metal content in grains, likely by modulating physiological responses and the plant’s heavy metal transport pathways. This study offers a novel approach to low-cost pre-sowing seed treatment for mitigating grain metal contamination.