Effect of biosorptive removal of cadmium ions from hydroponic solution containing indigenous garlic peel and mercerized garlic peel on lettuce productivity

•Cd stress adversely affects the growth and development of the lettuce plant.•A strong effect of Garlic peel on Cd toxicity alleviation has been observed.•Mercerized garlic peel decreased Cd content, the factor of translocation, biological accumulation factor, and tolerance index in shoots and roots.•Garlic peel improved lettuce plant growth under Cd toxicity.•Mercerized garlic peel reduced MDA, and increased proline, AsA, GSH content in both leaves and roots, alleviated Cd-induced oxidative stress by improving antioxidative systems.•Garlic peel displayed high expression levels of certain regulatory defense genes, UBC21, LOX, and PAL. One of the most harmful trace elements is cadmium (Cd) because of its persistence and high mobility. As Cd-contamination of soils increases worldwide, techniques to reduce the lettuce plant's Cd accumulation are required. The adverse effects of Cd can be reduced or eliminated using indigenous garlic peel (IGP) and, to a greater extent, mercerized garlic peel (MGP). In addition, the adsorption capacity of garlic peel after mercerization increased compared to indigenous garlic peel. This investigation explored the efficacy of IGP or MGP on the growth characteristics, Cd concentration, and biochemical processes in Cd-stress lettuce plants using a hydroponic growing system. The results demonstrated that IGP or MGP mitigated Cd's toxicity, improving lettuce growth, reducing Cd content, translocation factor, biological accumulation factor, tolerance index, malondialdehyde, and oxidative stress in both leaves and roots. In addition, the application of IGP and MGP significantly increased the non-enzymatic and enzymatic antioxidants in leaves and roots under Cd stress. Furthermore, all treated plants displayed high expression levels of certain regulatory defense genes, UBC21, LOX, and PAL. [Display omitted]