The intensity of tyrosine nitration is associated with selenite and selenate toxicity in Brassica juncea L

Ecotoxicol Environ Saf. 2018 Jan:147:93-101. doi: 10.1016/j.ecoenv.2017.08.038. Epub 2017 Sep 14.

Abstract

Selenium phytotoxicity involves processes like reactive nitrogen species overproduction and nitrosative protein modifications. This study evaluates the toxicity of two selenium forms (selenite and selenate at 0µM, 20µM, 50µM and 100µM concentrations) and its correlation with protein tyrosine nitration in the organs of hydroponically grown Indian mustard (Brassica juncea L.). Selenate treatment resulted in large selenium accumulation in both Brassica organs, while selenite showed slight root-to-shoot translocation resulting in a much lower selenium accumulation in the shoot. Shoot and root growth inhibition and cell viability loss revealed that Brassica tolerates selenate better than selenite. Results also show that relative high amounts of selenium are able to accumulate in Brassica leaves without obvious visible symptoms such as chlorosis or necrosis. The more severe phytotoxicity of selenite was accompanied by more intense protein tyrosine nitration as well as alterations in nitration pattern suggesting a correlation between the degree of Se forms-induced toxicities and nitroproteome size, composition in Brassica organs. These results imply the possibility of considering protein tyrosine nitration as novel biomarker of selenium phytotoxicity, which could help the evaluation of asymptomatic selenium stress of plants.

Keywords: Brassica juncea; Nitric oxide; Protein tyrosine nitration; Reactive nitrogen species; Selenate; Selenite.

MeSH terms

  • Biological Transport
  • Dose-Response Relationship, Drug
  • Hydroponics
  • Mustard Plant / drug effects*
  • Mustard Plant / metabolism
  • Nitro Compounds / metabolism*
  • Reactive Nitrogen Species / metabolism*
  • Selenic Acid / metabolism
  • Selenic Acid / toxicity*
  • Selenious Acid / metabolism
  • Selenious Acid / toxicity*
  • Tyrosine / metabolism*

Substances

  • Nitro Compounds
  • Reactive Nitrogen Species
  • Tyrosine
  • Selenious Acid
  • Selenic Acid