Glucosamine causes overproduction of reactive oxygen species, leading to repression of hypocotyl elongation through a hexokinase-mediated mechanism in Arabidopsis

Hyun Woo Ju, Eun Ji Koh, Sun Hee Kim, Kang Il Kim, Hojoung Lee, Suk Whan Hong

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Glucosamine (GlcN) is a naturally occurring amino-sugar that is synthesized by amidation of fructose-6-phosphate. Although a number of reports have examined the biological effects of GlcN on insulin resistance in mammalian systems, little is known about its effects on plant growth. In this study, we have shown that exogenous GlcN inhibits hypocotyl elongation in Arabidopsis, whereas glucose and its analogs alleviate this inhibitory effect. The hexokinase (HXK)-specific inhibitor mannoheptulose also restored hypocotyl elongation. The gin2-1 mutants with an alteration in AtHXK1 exhibited higher tolerance to GlcN. We also found that GlcN induces a significant increase in the production of reactive oxygen species (ROS). In addition, the GlcN-mediated inhibition of hypocotyl elongation was relieved by reducing agents such as ascorbic acid and glutathione. GlcN treatment resulted in significant induction of expression of GST1, GST2 and GST6, which are marker genes for ROS production. The gin2 mutation also represses the ROS production and the GST2 induction by GlcN treatment. Taken together, these results provide evidence that GlcN induces HXK-mediated induction of oxidative stress, leading to growth repression in Arabidopsis thaliana.

Original languageEnglish
Pages (from-to)203-212
Number of pages10
JournalJournal of Plant Physiology
Volume166
Issue number2
DOIs
Publication statusPublished - 2009 Jan 30

Keywords

  • Glucosamine
  • Glutathione-S-transferase
  • Hexokinase
  • Reactive oxygen species
  • gin2-1

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science
  • Plant Science

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