title: 28-homobrassinolide alters protein content and activities of glutathione-s-transferase and polyphenol oxidase in raphanus sativus L. Plants under heavy metal stress.
abstract: OBJECTIVE
  The application of brassinosteroids (BRs), the plant steroidal hormones, results in an increased tolerance toward stress and thus helps improving the yield of crop plants. The present study was carried out to investigate the effect of 28-homobrassinolide (28-HBL) on the protein content as well as activities of antioxidant enzymes viz., glutathione-s-transferase (GST) and polyphenol oxidase (PPO) in radish plants grown under Cadmium (Cd) and Mercury (Hg) metal stress.
  
  
  METHODS
  Shoots of 60 and 90 days old radish plants, grown under Cd and Hg metal stress (0, 0.5, 1.0, 1.5 mM) and given the presowing treatment of 28-HBL (0, 10(-7), 10(-9), 10(-11) M) to seeds for 8 h, were analyzed for protein content and GST and PPO enzyme activities.
  
  
  RESULTS
  Protein content showed decrease in plants given Cd and Hg metal treatment alone, while treatment with 28-HBL enhanced the protein content, suggesting its stress protective role. An increase in the activity of antioxidative enzymes was also observed in plants stressed with heavy metals as well as in those supplemented with 28-HBL.
  
  
  CONCLUSIONS
  In the present investigation, the activity of antioxidative enzymes was found to increase due to metal stress and a further increase was noticed in plants given both metal and 28-HBL treatment, suggesting the stress protective role of 28-HBL via modulating the antioxidative enzymes.
authors.affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
authors.forename: Gurjinder Singh
authors.initials: GS
authors.lastname: Hundal
authors.affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
authors.forename: Indu
authors.initials: I
authors.lastname: Sharma
authors.affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
authors.forename: Renu
authors.initials: R
authors.lastname: Bhardwaj
keywords: 28-HBL; Raphanus sativus L.; glutathione-s-transferase; polyphenol oxidase
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