干旱条件下大豆叶片H_2O_2代谢变化及其同抗旱性的关系

干旱条件下大豆叶片H_2O_2含量增加,AsA POD与 GR活性均表现“先上升后下降”的趋势。叶片AsA与GSH含量均随干旱时间的延长而逐渐下降,而PPOD活性则持续增加。抗旱性较强的小粒大豆品种7605在干旱条件下能维持较强的 H_2O_2清除能力,H_2O_2累积较少。

Changes of Hydrogen Peroxide Metabolism in Drought Stressed Soybean Leaves and Its Relation to Drought Resistance

A small-seed variety 7605(drought-resistant) and a commonlycultivated variety Ludou No. 4(drought-sensitive) of soybean (Glycinemax L. Merr.) were subjected todrought by withholding water in potsunder natural conditions. The effect ofdrought on the activities of ascorbicacid perokidase (AsA POD ), glu-tathione reductase (GR), Phenol--spe-cific peroxidase (PPOD) and the con-tents of ascorbic acid (AsA) and re-duced glutathione (GSH) were stud-ied. Increasing duration of stress pro-duced a gradual decrease in the con-tents of AsA, GSH but increased con-tent of H_2O_2. The activities of AsAPOD, GR increased at first, then de-creased, while the activity of PPODincreased steadily in the leaf tissues ofboth varieties under stress for 6 days.After 6 days of water withholding, thedrought--resistant variety 7605 showedhigher activities of AsA POD and GR,higher GSH content and lower PPODactivity than the drought-sensitive va-riety Ludou No. 4. It is, therefore,conceivable that the perameters ofH-2O_2 metabolism may be taken as in-dices of drought resistance in soybeanvarieties.