Role of reactive oxygen species produced by NADPH oxidase in gibberellin biosynthesis during barley seed germination

Plant Signal Behav. 2016 May 3;11(5):e1180492. doi: 10.1080/15592324.2016.1180492.


NADPH oxidase catalyzes the production of the superoxide anion (O2(-)), a reactive oxygen species (ROS), and regulates the germination of barley (Hordeum vulgare L.). Diphenyleneiodonium (DPI) chloride, an NADPH oxidase inhibitor, delayed barley germination, and exogenous H2O2 (an ROS) partially rescued it. Six enzymes, ent-copalyl diphosphate synthase (CPS), ent-kaurene synthase (KS), ent-kaurene oxidase (KO), ent-kaurenoic acid oxidase (KAO), GA20-oxidase (GA20ox) and GA3-oxidase (GA3ox), catalyze the transformation of trans-geranylgeranyl diphosphate to active gibberellin, which promotes germination. Exogenous H2O2 promoted the expressions of HvKAO1 and HvGA3ox1 in barley embryos. These results suggest that ROS produced by NADPH oxidase are involved in gibberellin biosynthesis through the regulation of HvKAO1 and HvGA3ox1.

Keywords: Gibberellin; NADPH oxidase; reactive oxygen species; seed germination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Plant / drug effects
  • Germination* / drug effects
  • Germination* / genetics
  • Gibberellins / biosynthesis*
  • Hordeum / drug effects
  • Hordeum / enzymology*
  • Hordeum / genetics
  • Hordeum / growth & development*
  • NADPH Oxidases / metabolism*
  • Onium Compounds / pharmacology
  • Reactive Oxygen Species / metabolism*
  • Seedlings / drug effects
  • Seedlings / growth & development
  • Seeds / growth & development*
  • Seeds / metabolism*


  • Gibberellins
  • Onium Compounds
  • Reactive Oxygen Species
  • diphenyleneiodonium
  • NADPH Oxidases