The present study investigated the effect of seed pretreatment with sodium nitroprusside (SNP) as nitric oxide (NO) donor on glyoxalase and antioxidant systems in germinating maize (Zea mays L.) seeds under methylglyoxal (MG) toxicity. The seeds were soaked in SNP solutions (0.0, 0.5, and 0.75 mM) for 8 h at 25 °C and then germinated in 0.0 (control) and 3 mM MG medium for 5 days under dark conditions (25 ± 1 °C and 75% humidity). The MG alone caused a strong inhibition on seed germination and seedling growth (root and shoot length) while the SNP pretreatments improved the same parameters in the MG-stressed seedlings. The MG alone increased endogenous MG accumulation, and glyoxalase I (Gly-I) and Gly-II activities eliminating MG toxicity in both organs. In contrast, the SNP pretreatments reduced MG content and further stimulated both enzyme activities in MG-stressed seedlings. MG alone increased reactive oxygen species (ROS) such as O₂^.− and H₂O_2, and lipid peroxidation (as malondialdehyde, MDA) levels. But the SNP pretreatments decreased ROS level, except for MDA content in seedlings exposed to MG. Moreover, MG alone stimulated superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) activities while it inhibited guaiacol peroxidase (GPX) activity. SNP pretreatments in seedlings stressed by MG further elevated SOD, GPX, and GR activities while it inhibited CAT and APX activities. The results showed that seed pretreatment with NO (particularly as 0.75 mM SNP) in maize seedlings exposed to MG ameliorated seed germination, seedling growth, MG accumulation, and oxidative stress by restoring the glyoxalase and antioxidant enzyme activities.

本研究调查了用硝普钠 (SNP) 作为一氧化氮 (NO) 供体对种子进行预处理对发芽玉米 ( Zea mays ) 中乙二醛酶和抗氧化系统的影响。L.) 甲基乙二醛 (MG) 毒性下的种子。种子在 SNP 溶液（0.0、0.5 和 0.75 mM）中在 25°C 下浸泡 8 小时，然后在 0.0（对照）和 3 mM MG 培养基中在黑暗条件（25±1°C 和 75 ％ 湿度）。单独的 MG 对种子萌发和幼苗生长（根和芽长度）产生强烈抑制，而 SNP 预处理改善了 MG 胁迫幼苗的相同参数。MG 单独增加内源性 MG 积累，乙二醛酶 I (Gly-I) 和 Gly-II 活性消除了两个器官中的 MG 毒性。相比之下，SNP 预处理降低了 MG 含量并进一步刺激了 MG 胁迫的幼苗中的两种酶活性。MG 单独增加活性氧 (ROS)，如 O ₂ ^.−和 H ₂ O_2、脂质过氧化（如丙二醛，MDA）水平。但 SNP 预处理降低了 ROS 水平，除了暴露于 MG 的幼苗中的 MDA 含量。此外，MG 单独刺激超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、抗坏血酸过氧化物酶 (APX) 和谷胱甘肽还原酶 (GR) 活性，同时抑制愈创木酚过氧化物酶 (GPX) 活性。MG 胁迫的幼苗中的 SNP 预处理进一步提高了 SOD、GPX 和 GR 的活性，同时抑制了 CAT 和 APX 的活性。结果表明，在暴露于 MG 的玉米幼苗中用 NO（特别是 0.75 mM SNP）进行种子预处理，通过恢复乙二醛酶和抗氧化酶的活性，改善了种子萌发、幼苗生长、MG 积累和氧化应激。