Catalyzes the conversion of hemimercaptal, formed from methylglyoxal and glutathione, to S-lactoylglutathione (By similarity). Involved in the detoxifiation of methylglyoxal. Can functionally complement growth defect of a yeast mutant lacking GLY I. Involved in abiotic stress response. Over-expression of GLYI-11 in tobacco increases tolerance to osmotic, oxidative and salt stresses (PubMed:24661284). (R)-S-lactoylglutathione = glutathione + methylglyoxal Binds 1 nickel ion per subunit. Optimum pH is 7.2. Secondary metabolite metabolism; methylglyoxal degradation; (R)-lactate from methylglyoxal: step 1/2. Monomer. Expressed in callus, stem, leaves, panicles and maturing seeds (at protein level). By salt stress and hydrogen peroxide (PubMed:21213008). Induced by methylglyoxal (PubMed:24661284). Phosphorylated after gibberellin treatment. Causes an allergic reaction in human. Binds to IgE. Plants over-expressing GLYI-11 display increased tolerance to osmotic, oxidative and salt stresses. Belongs to the glyoxalase I family.