Biochemical and molecular response of heavy metals phytoremediation in cotton genotypes

Heavy metal pollution is major environmental and public health concern because of the widespread toxicity of metals such as Cd and Pb. Using cotton crops for phytoremediation offers sustainable and environmental solution to heavy metal pollution. A pot experiment was conducted to evaluate the phytoremediation capability of six cotton genotypes for their phytoremediation capability, including Cocker310, Lachata, Pak-Cot, Montana, Spearo888, and W888, exposed to Cd (450 mg kg^-1) and Pb (1350 mg kg^-1) stresses. To achieve this, morphological, biochemical, and molecular evaluation has been made. The results highlighted genotype-dependent variation in response to heavy metal stress. Cocker310, Lachata, and Montana genotypes have relative tolerance to Cd and Pb stress. While W888, Spearo 888, and Pak-Cot showed considerable growth reduction, suggesting higher metabolic reduction associated with detoxification. The antioxidant system was enhanced to contribute to oxidative stress amelioration. The analysis of phytoremediation analysis indicated that Cd mobility and removal were higher in comparison with Pb. Cocker310, W888, and Spearo888 showed superior Cd accumulation, while Cocker310 showed enhanced Pb removal and translocation. The upregulated expression of GhHMA1 is related to heavy metal translocation, while PCS1 expression is involved in intracellular sequestration. In conclusion, selecting suitable genotypes can enhance phytoremediation in contaminated environments.