Effects of sodium nitroprussid and calcium silicate on the physiological and biochemical parameters of wheat (Triticum aestivum L.) under cadmium stress

Cadmium is a heavy metal with high toxicity that causes oxidative stress in plants and animals. heavy metal stress tolerance in plants with increasing levels of reactive oxygen species (ros) require using antioxidative pathways. hydroponic experiments were performed with thirteen treatments consisting of a control wheat plants not receiving heavy metal stress (cdso4) and the ameliorative factors casio3 and sodium nitroprussid (snp) and also plants treated with cdso4 at 25, 50, 75, and l00 μm concentrations with or without 1.5 mm snp or casio3. leaf samples from 60-day-old plants were used for determination of activities of ascorbate peroxidase, peroxidase, and polyphenol oxidase enzymes and also chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, mda, and proline contents. results indicated that cadmium decreased chlorophyll a, b, total chlorophyll, and carotenoid contents significantly while it increased ascorbate peroxidase, peroxidase, and polyphenol oxidase activities specially by adding casio3. also, polyphenol oxidase activity increased under cd stress significantly, which further increased by adding the ameliorative factor casio3. moreover, mda and proline contents increased under cd stress significantly, which decreased by adding ameliorative factors especially casio3. it was concluded that silicate enhances the cd tolerance in triticum aestivum l., which is attributed to its ameliorative effects as it suppresses cdso4 uptake and root to shoot cdso4 transport. in addition, the ameliorative effects of silicate enhance the plants’ antioxidant defense mechanisms.