24-Epibrassinolide mitigates the adverse effects of manganese induced toxicity through improved antioxidant system and photosynthetic attributes in Brassica juncea

• Published in: Environmental science and pollution research international Vol. 22; no. 15; pp. 11349 - 11359
• Main Authors: Fariduddin, Qazi, Ahmed, Mumtaz, Mir, Bilal A., Yusuf, Mohammad, Khan, Tanveer A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2015; Springer Nature B.V
• Subjects: Antioxidants; Antioxidants - pharmacology; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Brassica juncea; Brassinosteroids - pharmacology; Catalase - metabolism; Earth and Environmental Science; Ecotoxicology; Electrolyte leakage; Electrolytes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Enzymes; Flowers & plants; Heavy metals; Humidity; Hydrogen peroxide; Leaves; Lipid Peroxidation; Loam soils; Manganese; Manganese - toxicity; Manganese compounds; Metabolism; Mustard Plant - drug effects; Mustard Plant - enzymology; Oxidative Stress; Peroxidase - metabolism; Peroxidases - metabolism; Peroxidation; Photosynthesis; Plant growth; Plant Growth Regulators - pharmacology; Plant Leaves - drug effects; Plant Leaves - enzymology; Plant Proteins - metabolism; Plant sciences; Pollution studies; Proline - metabolism; Research Article; Seedlings; Seedlings - drug effects; Seedlings - enzymology; Seeds; Soil Pollutants - toxicity; Steroids, Heterocyclic - pharmacology; Superoxide Dismutase - metabolism; Toxicity; Waste Water Technology; Water Management; Water Pollution Control; Water relations; Lipid peroxidation; Manganese toxicity; Brassinosteroids; Photosynthesis; Antioxidant enzymes
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-4339-4

The objective of this study was to establish relationship between manganese-induced toxicity and antioxidant system response in Brassica juncea plants and also to investigate whether brassinosteroids activate antioxidant system to confer tolerance to the plants affected with manganese induced oxidative stress. Brassica juncea plants were administered with 3, 6, or 9 mM manganese at 10-day stage for 3 days. At 31-day stage, the seedlings were sprayed with deionized water (control) or 10 −8  M of 24-epibrassinolide, and plants were harvested at 45-day stage to assess growth, leaf gas-exchange traits, and biochemical parameters. The manganese treatments diminished growth along with photosynthetic attributes and carbonic anhydrase activity in the concentration-dependent manner, whereas it enhanced lipid peroxidation, electrolyte leakage, accumulation of H 2 O 2 as well as proline, and various antioxidant enzymes in the leaves of Brassica juncea which were more pronounced at higher concentrations of manganese. However, the follow-up application of 24-epibrassinolide to the manganese stressed plants improved growth, water relations, and photosynthesis and further enhanced the various antioxidant enzymes viz. catalase, peroxidase, and superoxide dismutase and content of proline. The elevated level of antioxidant enzymes as well as proline could have conferred tolerance to the manganese-stressed plants resulting in improved growth and photosynthetic attributes.