Unraveling the mechanisms of biochar and steel slag in alleviating lithium stress in tomato (Solanum lycopersicum L.) plants via modulation of antioxidant defense and methylglyoxal detoxification pathways

• Published in: Plant physiology and biochemistry 2024-10, Vol.215, p.109062, Article 109062
• Main Authors: Kapoor, Riti Thapar, Hasanuzzaman, Mirza
• Format: Article
• Language: English
• Subjects: Abiotic stress; Antioxidants - metabolism; Charcoal - pharmacology; Heavy metals; Industrial wastes; Lithium - metabolism; Lithium - pharmacology; Oxidative stress; Oxidative Stress - drug effects; Phytochelatin; Phytoremediation; Pyruvaldehyde - metabolism; ROS; Solanum lycopersicum - drug effects; Solanum lycopersicum - metabolism; Steel
• ISSN: 0981-9428; 1873-2690; 1873-2690
• DOI: 10.1016/j.plaphy.2024.109062

With progress in technology, soaring demand for lithium (Li) has led to its release into the environment. This study demonstrated the mitigation of the adverse effects of Li stress on tomato (Solanum lycopersicum L.) by the application of waste materials, namely coconut shell biochar (CBC) and steel slag (SS). To explore the impact of Li treatment on tomato plants different morphological, biochemical parameters and plant defense system were analyzed. Tomato plants exposed to Li had shorter roots and shoots, lower biomass and relative water contents, and showed decreases in physiological variables, as well as increases in electrolyte leakage and lipid peroxidation. However, the application of CBC and SS as passivators, either singly or in combination, increased growth variables of tomato and relieved Li-induced oxidative stress responses. The combined CBC and SS amendments reduced Li accumulation 82 and 90% in tomato roots and shoots, respectively, thereby minimizing the negative impacts of Li. Antioxidant enzymes SOD, CAT, APX and GR reflected 4, 5, 30, and 52% and glyoxalase enzymes I and II 7 and 250% enhancement in presence of both CBC and SS in Li treated soil, with a concurrent decrease in methylglyoxal content. Lithium treatment triggered oxidative stress, increased enzymatic and non-enzymatic antioxidant levels, and induced the synthesis of thiols and phytochelatins in roots and shoots. Hence, co-amendment with CBC and SS protected tomato plants from Li-induced oxidative damage by increasing antioxidant defenses and glyoxalase system activity. Both CBC, generated from agricultural waste, and SS, an industrial waste, are environmentally benign, safe, economical, and non-hazardous materials that can be easily applied on a large scale for crop production in Li-polluted soils. The present findings highlight the novel reutilization of waste materials as renewable assets to overcome soil Li problems and emphasize the conversion of waste into wealth and its potential for practical applications. [Display omitted] •Coconut shell biochar and steel slag increased tomato plant growth under Li stress.•Accumulation of osmolytes under combined CBC and SS treatment, strengthened ROS scavenging mechanisms.•Li stress increased thiol and phytochelatin contents in roots and shoots.•Biochar and steel slag reduced oxidative damage by altering antioxidant defense.