Methylglyoxal: An Emerging Signaling Molecule in Plant Abiotic Stress Responses and Tolerance

Abstract

The oxygenated short aldehyde methylglyoxal (MG) is produced in plants as a by-product of a number of metabolic reactions, including elimination of phosphate groups from glycolysis intermediates dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. MG is mostly detoxified by the combined actions of the enzymes glyoxalase I and glyoxalase II that together with glutathione make up the glyoxalase system. Under normal growth conditions, basal levels of MG remain low in plants; however, when plants are exposed to abiotic stress, MG can accumulate to much higher levels. Stress-induced MG functions as a toxic molecule, inhibiting different developmental processes, including seed germination, photosynthesis and root growth, whereas MG, at low levels, acts as an important signaling molecule, involved in regulating diverse events, such as cell proliferation and survival, control of the redox status of cells, and many other aspects of general metabolism and cellular homeostases. MG can modulate plant stress responses by regulating stomatal opening and closure, the production of reactive oxygen species, cytosolic calcium ion concentrations, the activation of inward rectifying potassium channels and the expression of many stress-responsive genes. MG appears to play important roles in signal transduction by transmitting and amplifying cellular signals and functions that promote adaptation of plants growing under adverse environmental conditions. Thus, MG is now considered as a potential biochemical marker for plant abiotic stress tolerance, and is receiving considerable attention by the scientific community. In this review, we will summarize recent findings regarding MG metabolism in plants under abiotic stress, and evaluate the concept of MG signaling. In addition, we will demonstrate the importance of giving consideration to MG metabolism and the glyoxalase system, when investigating plant adaptation and responses to various environmental stresses.

Impact of inorganic salts on vase life and postharvest qualities of the cut flower of Perpetual Carnation

“…Oxidative stress led to senescence in ornamental CFs occurs due to the presence of bacteria and fungi vase solution (Zhang et al, 2011). Antioxidant enzymes are vital in protecting the cell from pathogens by reducing the oxidative stress and water loss (Hoque Hossain et al, 2016;Khalid et al, 2018;Khalid et al, 2019). MDA is a product of membrane lipid peroxidation during the senescence process (Zafar et al, 2019) .…”

Upregulation of antioxidant and glyoxalase systems mitigates NaCl stress inBrassica junceaby supplementation of zinc and calcium

“…AsA-Glu cycle uses ascorbate as electron donor and reduces H 2 O 2 to H 2 O (Smirnoff 2000). Methylglyoxal (MG) is highly reactive and is elevated under abiotic stress (Yadav et al 2005, Hoque et al 2012, Hoque et al 2016. Plants are equipped with glutathione (GSH)-dependent glyoxalase (Gly) system to tackle this MG stress.…”

Al-induced proteomics changes in tomato plants over-expressing a glyoxalase I gene

“…Plants, when exposed to Al 3+ ions, experience direct injury from the toxic ions as well as secondary physiological stresses including accumulation of many toxic metaoblites, such as reactive oxygen species (ROS), MG, and others 57 . The stress-induced overproduction of MG can cause alteration in gene expression, disruption of normal cellular functions and metabolic pathways and, in some instances the interference in signal transduction pathways due to protein modification can lead to cell death or arrest of growth 16,58,59 . Thus the accumulation of the MG exacerbates the cellular damages from Al toxicity.…”