The accumulation, antioxidant defences, and secondary metabolite production in common sage (Salvia officinalis L.) under lead toxicity
antioxidants; Pb stress; rosmarinic acid; Sage; Salvia officinalis
The growing levels of lead (Pb) in agricultural soil and water bodies as a result of industrialization and human activity present serious challenges for medicinal plants. The present study investigates the complex responses of Salvia officinalis to toxicity caused by Pb including metal accumulation, translocation dynamics, antioxidant defenses, and the production of secondary metabolites. Pb showed preferential accumulation in the roots, peaking at (1000 ppm Pb) (2484.2 mg kg-1). The reduced levels of total chlorophyll (1.29-fold), protein (1.9-fold), and carbohydrate (2.5-fold) under prolonged exposure to stress demonstrate the toxic impacts of lead. Proline and total phenolic content (TPC) increased concentration-dependently under lead stress, while flavonoids were found to be decreased with the enhancement of lead toxicity. Enzymatic antioxidants (catalase, APX, and SOD) showed notable increase, especially in the 30 days of treatment, demonstrating the plants strong defenses. S. officinaliss adaptive responses were highlighted by concentration-dependent increases in non-enzymatic antioxidants such as total antioxidant capacity (TAC) and DPPH radical scavenging activity. Crucially, under lead stress, S. officinalis showed 1.7-fold increased rosmarinic acid (RA) production, in plants exposed to 200 ppm for 30 days treatment. However, further exposure to lead significantly caused the reduction of RA production. The results add to our knowledge of how sage plants respond to environmental stress and offer important insights for future uses in phytoremediation and the breeding of stress-tolerant plant cultivars. Furthermore, the research highlights about the S. officinaliss potential as a source of bioactive compounds possessing antioxidant qualities, under low levels of lead stress. 2024, Indian journals. All rights reserved.
Medicinal Plants, Vol-16, No. 3, pp. 519-531.
Ramakrishnan R., Department of Life Sciences, School of Sciences, CHRIST (Deemed to be University), Hosur Road, Karnataka, Bengaluru, 560029, India; Nagella P., Department of Life Sciences, School of Sciences, CHRIST (Deemed to be University), Hosur Road, Karnataka, Bengaluru, 560029, India