作　　者： ; ; ; ;

机构地区： 浙江师范大学化学与生命科学学院

出　　处： 《植物营养与肥料学报》 2005年第5期659-664,共6页

摘　　要： 采用溶液培养方法研究不同的镁水平对两个大豆品种在五叶期和盛花期叶片细胞膜透性和保护酶活性的变化.结果表明,在缺镁胁迫下,大豆叶片的质膜透性(MP)和丙二醛(MDA)含量显著增加,产生的活性氧物质诱导超氧化物歧化酶(SOD)和过氧化物酶(POD)活性升高,而过氧化氢酶(CAT)活性下降;而施镁则能明显降低大豆叶片MP和MDA含量,提高CAT活性,有利于大豆抗膜脂过氧化胁迫.在施镁1 ～ 10 mg/L浓度下,大豆叶片的质膜透性和MDA以及SOD和POD活性均达最低值,而CAT活性则达最高值.说明在低镁胁迫下,大豆叶片的CAT活性受到抑制,而适量施镁则大大增强了CAT活性,有利于大豆体内活性氧的清除和抗逆境胁迫能力的提高.各处理下,大豆盛花期SOD和CAT活性明显降低,说明随着时间的延长,大豆叶片细胞内产生过多的活性氧超出了酶的防御能力,造成了酶活性伤害,而POD活性则变化不大; 说明POD对活性氧具有较强的耐受性,是盛花期时起主要清除活性氧的作用的保护酶.本试验表明,大豆体内保护系统所存在的酶类在抵御逆境胁迫中相互协调,协同抗氧化. This study focused on the changes of cell membrane permeability and activities of protective enzymes at two developmental stages in soybean leaves of two pot-grown soybean varieties under different supplementation of magnesium concentration（Mg^＋ 0.00,0.01,0.10, 1.00, 10.00,100.00 mg/L） using solution culture. The results indicated that membrane permeability （MP）, malondialdehyde （MDA） significantly rose under the stress of Mg, while and catalase （CAT） activity declined. Meanwhile, the active oxygen that was produced by Mg stress leaded to an increase of superoxide dismutase （SOD）, peroxidase （POD） activities. Application of Mg decreased the MP and the MDA content and raised the CAT activity significantly indicating that Mg could improve anti-oxidant capacity of soybean leaves, among which the effects at Mg^＋ 1.00--10.00 mg/L was the best. Under this condition, the MP and the MDA content of soybean leaves and the activities of SOD and POD were the lowest, while the CAT activity were the highest. Mg deficiency inhibited the CAT activity that could be rectified by rational Mg application. We could conclude that rational application of Mg was favor of clearing up of active oxygen and proving stress tolerance ability. In addition, comparing SOD and CAT at these two stages, both them declined at full bloom stage. This means that the overabundance active oxygen produced in the leave cells of soybean have already beyond the recovery capacity of enzyme resulted in the harm of enzyme, while the POD activity changed slightly indicating POD was of greater stress tolerance capacity and was the dominant protectiveenzyme to eliminate the active oxygen. Therefore, the protective enzymes in the soybean protective system was harmonized each other and synergized against the oxidization.

关 键 词： 大豆 镁 细胞膜透性 保护酶

领　　域： [农业科学] [生物学]