腐植酸对干旱胁迫下谷子幼苗叶片抗坏血酸-谷胱甘肽循环的影响

为探讨腐植酸（HA）对干旱胁迫下谷子抗氧化系统的调节机制,以晋谷21号和张杂10号为材料,采用浸种法研究了不同浓度腐植酸（0、50、100、200、300mg/L）对干旱胁迫下谷子幼苗叶片抗坏血酸-谷胱甘肽（AsA-GSH）循环的影响。结果显示,100和200mg/L腐植酸处理显著提高了干旱胁迫下谷子幼苗叶片抗坏血酸过氧化物酶（APX）和脱氢抗坏血酸还原酶（DHAR）的活性,促进了抗氧化物质AsA和GSH的再生,使AsA/DHA和GSH/GSSH值增加,有效缓解了活性氧的积累。研究表明,腐植酸可通过提高AsA-GSH循环相关酶活性及抗氧化物质含量,缓解干旱胁迫对谷子幼苗造成的氧化损伤,从而提高谷子的抗旱性。

Effects of Humic Acid on Ascorbate-Glutathione Cycle in the Leaves of Foxtail Millet Seedlings under Drought Stress

To explore the regulation mechanism of humic acid on the antioxidant system of foxtail millet under drought stress, using Jingu 21 and Zhangza 10 as materials, the seed soaking method was used to study different concentrations of humic acid (0, 50, 100, 200, 300mg/L) on the ascorbate-glutathione (AsA-GSH) cycle of millet seedling leaves under drought stress. The results showed that 100 and 200mg/L humic acid treatment significantly increased the ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) activities of millet seedling leaves under drought stress, promoted the regeneration of AsA and GSH, increased the ratios of AsA/DHA and GSH/GSSH, and effectively alleviated the accumulation of reactive oxygen of millet seedlings. Therefore, humic acid could alleviate the oxidative damage of drought stress to the seedlings of foxtail millet by increasing the activity of metabolizing enzyme and the content of antioxidants in the AsA-GSH cycle, thus improved the drought resistance of foxtail millet.