不同水分条件下沙漠豆生理指标的变化

运用常规的植物生理抗旱性测定方法,对引种植物沙漠豆在不同土壤水分梯度下叶片中的可溶性糖、可溶性蛋白质、脯氨酸以及过氧化氢酶（CAT）活性,超氧化物歧化酶（SOD）活性和过氧化物酶（POD）3种保护酶等指标的变化进行研究。结果表明：1）脯氨酸含量随干旱胁迫程度的增强逐渐升高,可溶性蛋白质先降低后升高,二者之间存在相互补偿关系,可溶性糖含量呈现先升高再降低的变化趋势,表现出渗透调节物质对干旱的调节作用;2）3种保护酶活性在不同水分处理过程中变化不同,CAT活性表现为升高,SOD在中度干旱水分条件下升高,至重度干旱水分条件下则降低,POD活性的变化与SOD活性变化相反,保护酶之间相互配合协同作用维持了沙漠豆叶片细胞膜的完整性;3）丙二醛浓度随干旱胁迫程度的增强而升高,表明沙漠豆随水分不足可以通过增加渗透调节物质含量、增强保护酶活性、提高抗氧化能力,来减轻干旱胁迫的伤害。

Physiological changes of Swainsona formosa under different water conditions

Under different water conditions some physiological indexes of Swainsona formosa,such as Malondialdehyde（MDA）,soluble sugar,soluble protein,proline,protective enzymes（SOD,POD and CAT）,were determined by using the conventional method of plant physiology in this paper.The results are as follows：1） with increased drought stress the proline content increased gradually,soluble protein content decreased and the increased,there was a mutual compensation relationship between the two indexes.The tendency of content of soluble sugar increasing initially and then decreasing showed the regulation function of osmotic adjustment material to the drought stress.2） The activities of defense enzymes changed differently under various water conditions,the CAT activities raised with the drought stress.The SOD activity increased at moderate drought stress and declined at severe drought stress.In contrast to SOD activity,but POD activity changes were opposite to SOD.The cooperative synergistic effect among protective enzymes maintained the integrity of cell membrane of leaves.3） The MDA content increased with drought stress,which means that damage to.Swainsona formosa due to drought stress can be reduced by increasing soluble content,strengthening activity of protective enzymes and antioxygenic ability.