pH缓冲液对不同水分状态下冬小麦幼苗抗氧化酶活性的影响

Effects of pH Buffers on the Activities of Antioxidant Enzymes in Winter Wheat Seedlings under Different Water Status

为了解外源pH缓冲液对冬小麦幼苗抗旱性的影响,在温室条件下,采用负水头供水控水盆栽装置,测定和分析了不同供水(正常水分、轻度干旱和中度干旱)和叶片喷施不同pH磷酸缓冲液(以喷施清水为对照)条件下小麦叶片的相对电导率、活性氧代谢能力及抗氧化酶活性。结果表明,干旱胁迫使膜系统受到伤害,导致叶片相对电导率增加。在干旱胁迫下喷施pH缓冲液降低了叶片相对电导率、O2-产生速率及H2O2含量,其中pH 6.0和pH 7.5缓冲液处理效果最明显。说明在干旱条件下喷施适宜的pH缓冲液能增强小麦的抗氧化能力,减轻干旱引起活性氧增多对细胞膜的伤害,提高植株抗旱能力。

To investigate the regulation effects of exogenous pH buffers on drought resistance in winter wheat seedlings, a pot device with water supplied by negative pressure was used to simulate field drought at different soil moisture by setting the water supply tension （WST） of the device at different value in the greenhouse, the relative electronic conductance, capability of active oxygen metabolism, the activities of antioxidant enzymes of leaves in winter wheat seedling treated with different pH buffers were investigated under drought stresses. The results showed that the ability of active oxygen metabolism, electrical conductivity and the activities of antioxidant enzymes in the leaves increased significantly when the plants were subjected to water stress. However, compared with control, the leaf superoxide production ratio, hydrogen proxide level and electrical conductivity decreased in the pH buffer treatments under water stress, of which obvious differences were observed at the pH 6.0 and pH 7.5 treatments, The results suggested that appropriate exogenous pH buffers could enhance the activities of wheat antioxidant enzymes under drought stress, slow down the damage of cell membrane caused by active oxygen under drought stress.