Yu Chih-Wen, Murphy Terence M, Sung Wei-Wen, Lin Chin-Ho
Botany Department, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Plant Biology, University of California, Davis, CA 95616, USA.
Funct Plant Biol. 2002 Aug;29(9):1081-1087. doi: 10.1071/PP01264.
Mung bean (Vigna radiata L. cv. TN5, a chilling-sensitive cultivar) was employed to evaluate the importance of glutathione in hydrogen peroxide (H2O2)-induced chilling tolerance. Seeds germinated at 25°C for 7d were subjected to different periods of chilling treatment, prior to analysis of the glutathione contents of their leaves. In a comparison of acclimation temperatures from 2-12°C, it was found that an 8°C acclimation for 36 h induced a 5.7-fold increase, the highest glutathione level among the temperatures tested. Seedlings acclimated at 8°C for 36 h showed 97% survival after a 36-h, 4°C chilling stress, compared with 33% survival of non-acclimated plants. Pretreatment with 200 mM H2O2 for 12 h before a 36-h, 4°C chilling treatment increased glutathione levels by 30% and reduced electrolyte leakage to 43%, relative to the untreated control. Treated seedlings also showed a survival rate of 71% after the same chilling treatment. Application of 1 mM buthionine sulfoximine, a specific inhibitor of glutathione synthesis, reversed the protection against chilling stress provided to seedlings either by acclimation at 8°C for 36 h or H2O2 pretreatment. The role of glutathione in chilling acclimation or H2O2-pretreatment-induced chilling tolerance is thus confirmed.
绿豆（Vigna radiata L. cv. TN5，一种冷敏感品种）被用于评估谷胱甘肽在过氧化氢（H2O2）诱导的冷耐受性中的重要性。在25°C下发芽7天的种子在分析其叶片谷胱甘肽含量之前，先进行不同时间段的冷处理。在2-12°C的驯化温度比较中，发现8°C驯化36小时可使谷胱甘肽水平增加5.7倍，这是测试温度中最高的谷胱甘肽水平。在4°C下进行36小时冷胁迫后，在8°C下驯化36小时的幼苗存活率为97%，而未驯化的植物存活率为33%。在4°C下进行36小时冷处理前，用200 mM H2O2预处理12小时，相对于未处理的对照，谷胱甘肽水平增加了30%，电解质渗漏减少到43%。经过相同冷处理后，处理过的幼苗存活率也为71%。应用1 mM丁硫氨酸亚砜胺（一种谷胱甘肽合成的特异性抑制剂）可逆转8°C驯化36小时或H2O2预处理为幼苗提供的抗冷胁迫保护作用。因此，证实了谷胱甘肽在冷驯化或H2O2预处理诱导的冷耐受性中的作用。
