Salicylic Acid Mitigates Cadmium Stress in Wheat: Experimental Insights Into Growth and Biochemical Parameters

The purpose of this study was to investigate the impact of salicylic acid (SA) on wheat subjected to cadmium (Cd) stress. The experiments were conducted during the winter season of 2022-2023 (November to February) at the University of the Punjab in Lahore, Pakistan. The study involved four wheat varieties: Akbar-2019, Galaxy-2013, Ujala-16, and Chakwal-86. The study utilized a factorial design with three replicates, examining three Cd levels (0.1 mM, 0.2 mM, and 0.3 mM) and two SA levels (0.5 mM and 0.9 mM). SA was applied as a seed priming agent, while cadmium sulfate (CdSO₄) solution induced Cd toxicity. Various growth parameters, including plant height, total plant length, leaf length, leaf breadth, and leaf area, were measured alongside physiological and biochemical parameters such as total chlorophyll content, carotenoid content, oxidative stress indicators (MDA and H₂O₂), and antioxidants (total soluble protein, CAT, and APX)-to assess the effects of SA under Cd stress. The results indicated that the application of 0.5 mM SA resulted in the highest vegetative growth and maximum physiological and biochemical parameters, while 0.3 mM Cd significantly reduced growth. The performance of the treatments was observed in the following order: 0.5 mM SA > 0.3 mM Cd. Ujala-16 showed intermediate growth and yield, while Chakwal-86 had the lowest growth rate and yield. The study demonstrated that SA mitigates Cd stress effects, with 0.9 mM SA and 0.1 mM Cd yielding the highest growth, second only to 0.5- and 0.9-mM SA treatments. These findings underscore the potential of SA to enhance wheat growth and yield in Cd-contaminated soils. In conclusion, SA is suggested as a beneficial treatment for improving productivity and economic returns in Cd-stressed areas. Future recommendations include conducting long-term studies to evaluate cumulative treatment effects and investigating how salicylic acid mitigates cadmium stress through biochemical pathways and gene expression, enhancing agricultural practices.