Selenium nanoparticles mitigate lead-induced genotoxicity and phytotoxicity in Pisum sativum by modulating LOX1 and JAR1 gene expression

This study investigated the effects of lead nitrate (Pb(NO3​)2​) at 90, 180, and 270 mg L-1 on pea (Pisum sativum L.) and evaluated the potential of selenium nanoparticles (SeNPs) at 10, 30, and 60 mg L-1 to alleviate lead-induced genotoxicity. We analyzed seedling and vegetative growth, DNA damage using the comet assay, and the expression profiles of the stress-related genes LOX1 and JAR1. Pb(NO3​)2​ significantly inhibited pea growth, leading to severe reductions in shoot and root lengths, biomass, and number of leaves. Conversely, SeNPs alone enhanced these growth parameters and effectively mitigated lead-induced phytotoxicity. The 60 mg L-1 SeNP treatment, especially when combined with lead, demonstrated the most pronounced improvement in shoot and root development. Comet assay analysis in leaf cells revealed a concentration-dependent increase in DNA damage following Pb(NO3​)2​ exposure. The highest genotoxicity, characterized by increased percentages of tailed DNA, tail lengths, and tail moments, was consistently observed with the 270 mg L-1 Pb(NO3​)2​ treatment, alone or combined with 10 mg L-1 SeNP. In contrast, the 60 mg L-1 SeNPs+90 mg L-1 Pb(NO3​)2​ treatment resulted in the lowest DNA damage among lead-exposed groups. Furthermore, 270 mg L-1 Pb(NO3​)2​ significantly upregulated LOX1 and JAR1 expression. The sole application of 60 mg L-1 SeNPs substantially reduced LOX1 expression below control levels. Notably, the 60 mg L-1 SeNP+270 mg L-1 Pb(NO3​)2​ combined treatment significantly downregulated the expression of both genes compared to the 270 mg L-1 Pb(NO3​)2​ treatment alone. These findings suggest that SeNPs can modulate lead-induced stress and mitigate genotoxicity in P. sativum by potentially influencing the LOX1 and JAR1 signaling pathways.