Effect of exogenous alpha-tocopherol on physio-biochemical attributes and agronomic performance of lentil (Lens culinaris Medik.) under drought stress

PLoS One. 2021 Aug 6;16(8):e0248200. doi: 10.1371/journal.pone.0248200. eCollection 2021.

Abstract

Water being a vital part of cell protoplasm plays a significant role in sustaining life on earth; however, drastic changes in climatic conditions lead to limiting the availability of water and causing other environmental adversities. α-tocopherol being a powerful antioxidant, protects lipid membranes from the drastic effects of oxidative stress by deactivating singlet oxygen, reducing superoxide radicals, and terminating lipid peroxidation by reducing fatty acyl peroxy radicals under drought stress conditions. A pot experiment was conducted and two groups of lentil cultivar (Punjab-2009) were exposed to 20 and 25 days of drought induced stress by restricting the availability of water after 60th day of germination. Both of the groups were sprinkled with α-tocopherol 100, 200 and 300 mg/L. Induced water deficit stress conditions caused a pronounced decline in growth parameters including absolute growth rate (AGR), leaf area index (LAI), leaf area ratio (LAR), root shoot ratio (RSR), relative growth rate (RGR), chlorophyll a, b, total chlorophyll content, carotenoids, and soluble protein content (SPC) which were significantly enhanced by exogenously applied α-tocopherol. Moreover, a significant increase was reported in total proline content (TPC), soluble sugar content (SSC), glycine betaine (GB) content, endogenous tocopherol levels, ascorbate peroxidase (APX), catalase (CAT) peroxidase (POD) and superoxide dismutase (SOD) activities. On the contrary, exogenously applied α-tocopherol significantly reduced the concentrations of malondialdehyde (MDA) and hydrogen peroxide (H2O2). In conclusion, it was confirmed that exogenous application of α-tocopherol under drought induced stress regimes resulted in membrane protection by inhibiting lipid peroxidation, enhancing the activities of antioxidative enzymes (APX, CAT, POD, and SOD) and accumulation of osmolytes such as glycine betaine, proline and sugar. Consequently, modulating different growth, physiological and biochemical attributes.

MeSH terms

  • Antioxidants / pharmacology*
  • Ascorbate Peroxidases / metabolism
  • Catalase / metabolism
  • Crop Production
  • Dehydration
  • Hydrogen Peroxide / metabolism
  • Lens Plant / drug effects
  • Lens Plant / growth & development*
  • Lens Plant / metabolism
  • Lipid Peroxidation / drug effects
  • Malondialdehyde / metabolism
  • Peroxidase / metabolism
  • Superoxide Dismutase / metabolism
  • alpha-Tocopherol / pharmacology*

Substances

  • Antioxidants
  • Malondialdehyde
  • Hydrogen Peroxide
  • Ascorbate Peroxidases
  • Catalase
  • Peroxidase
  • Superoxide Dismutase
  • alpha-Tocopherol

Grants and funding

No funding was given by any source to conduct this study but this study is a part of M.Phil/MS degree of Mr. Wadood Shah for which Botany Department, University of Peshawar, Pakistan provided the laboratory facilities.