Methylglyoxal (MG) now is found to be an emerging signaling molecule. It can relieve the toxicity of cadmium (Cd), however its alleviating mechanism still remains unknown. In this study, compared with the Cd-stressed seedlings without MG treatment, MG treatment could stimulate the activities of glutathione reductase (GR) and gamma-glutamylcysteine synthetase (γ-ECS) in Cd-stressed wheat seedlings, which in turn induced an increase of reduced glutathione (GSH). Adversely, the activated enzymes related to GSH biosynthesis and increased GSH were weakened by N-acetyl-L-cysteine (NAC, MG scavenger), 2,4-dihydroxy-benzylamine (DHBA) and 1,3-bischloroethyl-nitrosourea (BCNU, both are specific inhibitors of GR), buthionine sulfoximine (BSO, a specific inhibitors of GSH biosynthesis), and N-ethylmaleimide (NEM, GSH scavenger), respectively. In addition, MG increased the activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) in Cd-treated seedlings, followed by declining an increase in endogenous MG as comparision to Cd-stressed seedlings alone. On the contrary, the increased glyoxalase activity and decreased endogenous MG level were reversed by NAC and specific inhibitors of Gly I (isoascorbate, IAS; squaric acid, SA). Furthermore, MG alleviated an increase in hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) in Cd-treated wheat seedlings. These results indicated that MG could alleviate Cd toxicity and improve the growth of Cd-stressed wheat seedlings by a coordinated induction of glutathione pool and glyoxalase system.

现在发现甲基乙二醛（MG）是一种新兴的信号分子。它可以缓解镉（Cd）的毒性，但是其缓解机理仍然未知。在这项研究中，与未经MG处理的Cd胁迫幼苗相比，MG处理可以刺激Cd胁迫的小麦幼苗中的谷胱甘肽还原酶（GR）和γ-谷氨酰半胱氨酸合成酶（γ-ECS）的活性，从而诱导其增加。减少的谷胱甘肽（GSH）。不利的是，N-乙酰基-L减弱了与谷胱甘肽生物合成相关的活化酶和谷胱甘肽增加-半胱氨酸（NAC，MG清除剂），2,4-二羟基苄基胺（DHBA）和1,3-双氯乙基-亚硝基脲（BCNU，均为GR的特异性抑制剂），丁硫氨酸亚砜亚胺（BSO，GSH生物合成的特异性抑制剂） ，和N-乙基马来酰亚胺（NEM，GSH清除剂）。此外，MG增加了Cd处理的幼苗中的乙二醛酶I（Gly I）和乙二醛酶II（Gly II）的活性，随后与单独的Cd胁迫幼苗相比，内源性MG的增加下降。相反，NAC和Gly I的特异性抑制剂（异抗坏血酸盐，IAS；方酸，SA）可以逆转乙二醛酶活性的增加和内源性MG水平的降低。此外，MG减轻了过氧化氢（H ₂ O ₂）和Cd处理过的小麦幼苗中的丙二醛（MDA）。这些结果表明，通过协同诱导谷胱甘肽池和乙二醛酶系统，MG可以减轻Cd的毒性并改善Cd胁迫的小麦幼苗的生长。