Arabidopsis thaliana glyoxalase 2-1 is required during abiotic stress but is not essential under normal plant growth.
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.
Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
Sriram
S
Devanathan
Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.
Alexander
A
Erban
Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
Rodolfo
R
Perez-Torres
Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.
Joachim
J
Kopka
Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
Christopher A
CA
Makaroff
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D015687:Cell Hypoxia; D003198:Computer Simulation; D030541:Databases, Genetic; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D013312:Stress, Physiological; D013869:Thiolester Hydrolases / Q000235:genetics* / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism; D000099301:Hydroxyacylglutathione Hydrolase
D029681:Arabidopsis Proteins; D013869:Thiolester Hydrolases; D013912:Threonine; D000099301:Hydroxyacylglutathione Hydrolase