盐胁迫下两品种大麦叶片H_2O_2累积及其清除酶活性的变化

Changes of hydrogen peroxide accumulation and hydrogenperoxidescavenging enzyme activity in the leaves oftwo barley species under salt stress

以鉴４（Ｊ４，耐盐性较强）和科品７号（Ｋｐ７，耐盐性较弱）大麦叶片为材料，研究了在不同浓度盐处理下Ｈ２Ｏ２累积和Ｈ２Ｏ２清除酶的活性变化。结果表明，在３００ｍｍｏｌ／ＬＮａＣｌ处理７天期间，科品的Ｈ２Ｏ２累积量大于鉴４；两品种超氧化物歧化酶（ＳＯＤ）维持较高活性，鉴４的过氧化氢酶（ＣＡＴ）活性呈上升趋势，科品的却下降；鉴４清除Ｈ２Ｏ２能力大于科品，其中ＣＡＴ起关键作用。用５ｍｍｏｌ／ＬＨ２Ｏ２或０．５ｍｍｏｌ／Ｌ甘露醇处理盐胁迫中的大麦，能缓解盐对科品７号的胁迫作用。

The contents of H2O2 and the activities of H2O2scavenging enzymes of two barley species Hordeum vulgare LJ4(salttolerant)and Kepin 7(saltsensitive)]under different NaCl stress were studied.The results showed that the rate of H2O2 accumulation was faster in Kepin 7 than in J4,except the activity of CAT increased in J4 and decreased in Kepin 7,the activity of SOD maintained higher level under 300 mmol/L NaCl treatment during 7 days.Ability of H2O2scavenging was higher in J4 than in Kepin 7.CAT is key enzyme in the H2O2scavenging enzymes.The additional treatment of 5 mmol/L H2O2 or 05 mmol/L mannitol could delay the senscence process of barley leaves under salt stress.