Glyoxalase Systems in Plant Abiotic Stress Tolerance

Plants exposed to drought, salinity, heavy metals and extreme temperatures accumulate methylglyoxal (MG), a cytotoxic by‐product of glycolysis. The canonical glyoxalase system, comprising glyoxalase I (GLY I) and glyoxalase II (GLY II), uses reduced glutathione (GSH) to convert MG ultimately into D-lactate, thereby preventing glycation of proteins, nucleic acids and lipids. Under abiotic stress, upregulation or transgenic overexpression of GLY I and GLY II enhances MG detoxification, maintains GSH homeostasis and interconnects with antioxidant networks that scavenge reactive oxygen species (ROS). Recent identification of glyoxalase III (GLY III)–like enzymes in plants suggests a shorter, GSH‐independent route for MG detoxification. Regulation of glyoxalase genes involves transcriptional control, alternative splicing to target isoforms to specific organelles and post-translational modifications such as S-glutathionylation, which fine-tune enzyme activity. Collectively, these advances underscore the glyoxalase pathway’s central role in sustaining cellular redox balance and protecting plant growth under diverse environmental constraints, with direct implications for improving crop resilience globally.

Research from Nature Portfolio

Analyses of rice genomes have uncovered a family of DJ-1/PfpI domain proteins that function as glyoxalase III enzymes, converting MG directly into D-lactate without GSH. One member, OsDJ-1C, is constitutively expressed across tissues and strongly induced by exogenous MG. Biochemical assays and site-directed mutagenesis of the catalytic cysteine residue confirm its GSH-independent activity. The discovery of GLY III‐like proteins across monocots, dicots, gymnosperms and bryophytes points to a conserved, alternative detoxification pathway that may be harnessed to engineer stress tolerance in crops without perturbing GSH pools.

Glyoxalase Systems in Plant Abiotic Stress Tolerance publication trend

The graph below shows the total number of articles in glyoxalase systems in plant abiotic stress tolerance across all publications each year (not limited to Nature Index journals).

Technical terms

Glyoxalase system: Two‐enzyme pathway catalysing the conversion of methylglyoxal into non‐toxic compounds using glutathione.

Methylglyoxal (MG): Highly reactive α‐oxoaldehyde by‐product of glycolysis that can damage proteins, nucleic acids and lipids.

Glutathione (GSH): Low‐molecular‐weight tripeptide that serves as cofactor for glyoxalase and a central redox buffer in cells.

Reactive oxygen species (ROS): Partially reduced oxygen intermediates that accumulate under stress and cause oxidative damage.

S-glutathionylation: Reversible post-translational modification where glutathione binds to protein cysteine residues, regulating activity under stress.

References

1. Dose-dependent regulation of morphological, physio-biochemical, nutritional, and metabolic responses by cobalt in Tagestes erecta L. plants exposed to salinity stress. Plant Stress (2024).
2. Coordinated Actions of Glyoxalase and Antioxidant Defense Systems in Conferring Abiotic Stress Tolerance in Plants. International Journal of Molecular Sciences (2017).
3. Presence of unique glyoxalase III proteins in plants indicates the existence of shorter route for methylglyoxal detoxification. Scientific Reports (2016).
4. Glutathione Metabolism in Plants under Stress: Beyond Reactive Oxygen Species Detoxification. Metabolites (2021).