Elucidating arsenic-induced stress responses in maize genotypes: Unravelling biochemical, physiological, and nutrient...

Arsenic (As) contamination in agricultural systems threatens crop productivity and food safety. This study aimed to investigate the differential response of two maize genotypes, GD562 and GD911, to arsenic stress, with each parameter measured using three biological replicates per treatment. These genotypes were selected based on a multivariate analysis of data from a pot experiment involving 20 maize genotypes, aiming to identify those most suitable for further investigation. Morphological and biomass analyses revealed significant reductions in growth parameters. GD911 exhibited greater sensitivity to arsenic, with a 13 % reduction in plant height and a 40 % reduction in leaf area, compared to 4 % and 21 % reductions, respectively, in GD562. Photosynthetic performance was also differentially affected. GD562 showed a 20 % increase in chlorophyll content and smaller reductions in photosynthesis rate, stomatal conductance, and transpiration, while GD911 had a 40 % reduction in chlorophyll content and significant reductions in photosynthetic efficiency. Biochemical analysis revealed that GD562 exhibited a 45 % increase in ascorbate peroxidase activity and maintained superoxide dismutase activity more effectively. In contrast, GD911 reduced enzyme activity, increased oxidative stress, and higher lipid peroxidation and electrolyte leakage. Nutrient dynamics indicated that GD562 maintained stable iron and zinc concentrations, whereas GD911 exhibited significant reductions. Arsenic translocation and bioaccumulation were also genotype-dependent; GD562 restricted arsenic accumulation in grains, while GD911 showed higher translocation to grains. Yield per plant was reduced by 53.7 % in GD911 and 33.1 % in GD562. These findings underscore the significance of antioxidative defense and regulated arsenic translocation in developing stress-tolerant maize cultivars.