Arabidopsis thaliana glyoxalase 2-1 is required during abiotic stress but is not essential under normal plant growth

PLoS One. 2014 Apr 23;9(4):e95971. doi: 10.1371/journal.pone.0095971. eCollection 2014.

Abstract

The glyoxalase pathway, which consists of the two enzymes, GLYOXALASE 1 (GLX 1) (E.C.: 4.4.1.5) and 2 (E.C.3.1.2.6), has a vital role in chemical detoxification. In Arabidopsis thaliana there are at least four different isoforms of glyoxalase 2, two of which, GLX2-1 and GLX2-4 have not been characterized in detail. Here, the functional role of Arabidopsis thaliana GLX2-1 is investigated. Glx2-1 loss-of-function mutants and plants that constitutively over-express GLX2-1 resemble wild-type plants under normal growth conditions. Insilico analysis of publicly available microarray datasets with ATTEDII, Mapman and Genevestigator indicate potential role(s) in stress response and acclimation. Results presented here demonstrate that GLX2-1 gene expression is up-regulated in wild type Arabidopsis thaliana by salt and anoxia stress, and by excess L-Threonine. Additionally, a mutation in GLX2-1 inhibits growth and survival during abiotic stresses. Metabolic profiling studies show alterations in the levels of sugars and amino acids during threonine stress in the plants. Elevated levels of polyamines, which are known stress markers, are also observed. Overall our results suggest that Arabidopsis thaliana GLX2-1 is not essential during normal plant life, but is required during specific stress conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / enzymology
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism*
  • Cell Hypoxia
  • Computer Simulation
  • Databases, Genetic
  • Gene Expression Regulation, Plant
  • Mutation
  • Stress, Physiological
  • Thiolester Hydrolases / genetics*
  • Thiolester Hydrolases / metabolism*
  • Threonine / metabolism

Substances

  • Arabidopsis Proteins
  • Threonine
  • Thiolester Hydrolases
  • hydroxyacylglutathione hydrolase

Grants and funding

The work was supported in part from funds from Miami University. No additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.