Responses to lead stress in Scrophularia striata: insights into antioxidative defence mechanisms and changes in flavonoids profile

Funct Plant Biol. 2024 Apr:51:FP23236. doi: 10.1071/FP23236.

Abstract

Lead (Pb) induces oxidative stress in plants, which results in different responses, including the production of antioxidants and changes in the profile of secondary metabolites. In this study, the responses of Scrophularia striata exposed to 250mgL-1 Pb (NO3 )2 in a hydroponic environment were determined. Growth parameters, oxidative and antioxidative responses, redox status, and the concentration of Pb were analysed in roots and shoots. Malondialdehyde and hydrogen peroxide (H2 O2 ) levels in the roots were significantly increased and reached their highest value at 72h after Pb treatment. Superoxide dismutase, catalase, and peroxidase, as an enzymatic antioxidant system, were responsible for reactive oxygen species scavenging, where their activities were increased in the shoot and root of Pb-treated plants. Enzymatic antioxidant activities were probably not enough to remove a significant H2 O2 content in response to Pb treatment. Therefore, other defence responses were activated. The results stated that the flavonoid components of S. striata progressed towards the increase of isoflavone, flavanol, and stilbenoid contents under Pb treatment. In general, S. striata stimulates the enzymatic defence system and activates the non-enzymatic system by modulating the profile of flavonoids toward the production of flavonoids with high antioxidant activity, such as quercetin and myricetin in response to Pb stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants* / metabolism
  • Catalase / metabolism
  • Flavonoids* / metabolism
  • Hydrogen Peroxide* / metabolism
  • Lead* / metabolism
  • Lead* / toxicity
  • Malondialdehyde / metabolism
  • Oxidative Stress* / drug effects
  • Plant Roots* / drug effects
  • Plant Roots* / metabolism
  • Plant Shoots / drug effects
  • Plant Shoots / metabolism
  • Scrophularia* / metabolism
  • Superoxide Dismutase / metabolism

Substances

  • Antioxidants
  • Lead
  • Flavonoids
  • Hydrogen Peroxide
  • Malondialdehyde
  • Superoxide Dismutase
  • Catalase