VESICULAR ARBUSCULAR MYCORRHIZA AND BRASSINOSTEROIDS AMELIORATESTHE EFFECTS OF STUNTED GROWTH AND OXIDATIVE STRESS INDUCED BY LEAD

The growth and metabolic activities in plants are prominently influenced by the biotic and abiotic stress. Different biofertilizers and phytohormone are used as bio-stimulant to mitigate these stresses to sustain plant physiological output. Trace metals such as lead (Pb) toxicity is a threat to vegetation and induce impairments in morphological and biochemical attributes. Vesicular arbuscular mycorrhizae (VAM) and Brassinosteroids (BRs) possess beneficial physiological responses and bioremediation capabilities to resist different stresses including heavy metals stress in plants. This study will assess the mitigating effects of VAM and BRs on metabolism and growth of Luffa cylindrica plants affected by the lead trace metal. Growth (shoot and root length, plant fresh and dry weight), biochemical analysis (protein, carbohydrate, phenol and photosynthetic pigments) and antioxidant levels (Malondialdehyde (MDA), Peroxidase (POD) and Superoxide dismutase (SOD) enzymes activities were examined to assess the efficacy of applied biostimulants. L.cylindrica plant treated with (Pb) showed a significant reduction in physiological and biochemical parameters compared to control, VAM and BRs treated plants. Plants grown under Pb trace metal showed highest MDA levels compared with other treatments. Plants exposed to the combined application of VAM and BRs bio-stimulant enhanced growth, biochemical and antioxidant defense compared to their individual treatments. The results of morphological and biochemical analysis revealed that the synergic treatment of VAM and Brassinosteroids enhanced the plant adaptations to resist metal toxicity caused by lead (Pb). In conclusion, the combined application of VAM and BRs could be applied as biofertilzer to enhance the plant growth and provide the formulations methods to remediate the Pb trace metal polluted soil to maintain environmental safety and ecotoxicology.