Glucose modulate Photosynthesis, Antioxidant System and Morphophysiology in Tomato (Solanum lycopersicum) Plants under Cadmium Stress

CADMIUM (Cd), a heavy metal that naturally exists in soil, is dangerous for plants, animals, and humans to be in contact with. The primary causes of Cd contamination in soil include manure, sewage sludge, aerial deposition, and excessive use of phosphate fertilizers. Cd toxicity significantly reduced the crop productivity and physio-biochemical attributes. Present research aim was to investigate the effect of glucose in Solanum lycopersicum under Cd stress. Seeds of S. lycopersicum soaked in 50 mM of glucose for 5hrs followed by sown in the maintain pots. Cd stress (0.8 mM) was applied directly through the soil at the stage of 15 days. Results of this study demonstrated that Cd stress reduced the length (shoot and root by 41 and 70%), weight (fresh [32 & 66%] and dry [28 & 29%]), SPAD value, photosynthesis and related characteristics, carbonic anhydrase (CA) and nitrate reductase (NR). Beside this, malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content increased in the presence of Cd in S. lycopersicum plants. However, pre-treatment of glucose partially or fully counteracted the toxicity triggered by Cd in the aforesaid parameters. Moreover, antioxidant enzymes activity and proline content are further increased in the plants which previously received glucose through seeds. Our study reveals the beneficial effects of glucose for improved growth and will support new avenue on overcoming Cd toxicity and improving agricultural productivity.