盐胁迫对大豆幼苗子叶各细胞器超氧化物歧化酶(SOD)的影响

大豆幼苗子叶各细胞器的SOD活性以细胞溶质为最高,约占80％;线粒体次之,为11％;叶绿体部分最少,9.0％左右。各细胞器的SOD对盐胁迫反应敏感程度不同,依次为叶绿体>线粒体>细胞溶质。品种间,各细胞器之间以及对照和处理间差异均达到显著水平,10ds/m和15ds/m差异不显著。电泳酶谱的扫描结果表明,在盐胁迫条件下SOD_a(Mn SOD)最为稳定,SODb_1b_2b_3、SODc_1c_2c_3(Cu—Zn—SOD)将随盐胁迫增强依次从叶绿体到线粒体,从SODc_3、SODc_2到SODc_1、SODb_3逐渐减弱或消失。耐盐品种和敏感品种的主要差异集中在叶绿体SOD酶谱上,推断SODc_1c_2c_3与大豆耐盐性有关。

The Effect of Salt Stress on Superoxide Dismutase in Various Organelles from Cotyledon of Soybean Seedling

The localization of superoxide dismutase (SOD) in various organelles fromcotyledon of soybean seedling was characterized. The results showed that about 80%, 11% and 9% of tatal SOD activity were present in cytosol, mitochondria and choroplast, respectively. The sensitivities of SOD in various organelles to salt stress were different, with the highest in chloro-plast, then in mitochondria and the most tolerant in cytosol. The NAOVA showed that there are significant difference among varieties, organelles and salt treatments, but no significant was found between 10ds/m and 15 ds/m NaCl treatments. The scanning of electrophoresis bands indicated that SODa band is the stablest one under salt stress condition and the activity of SODb1b2b3 bands and SODc1c2c3 bands decreased or disappeared from choroplast to mitochondria with the order from c3 to c2, c1 and b3 band as the salt stress increased. The difference between sensitive and tolerant varieties to salt stress was mainly in SOD zymogram of choroplast. It is deduced that SODc1c2c3 bands are closely related to the soybean salt tolerance.