不同生境下两种表型盐地碱蓬叶片POD比较研究

THE COMPARATIVE STUDY ON POD IN THE LEAVES OF TWO DIFFERENT PHENOTYPE OF SUAEDA SALSA L. GROWN UNDER DIFFERENT NATURAL CONDITIONS

以不同自然生境下两种表型盐地碱蓬叶片为材料,分析了H2O2含量、MDA含量、质膜透性、过氧化物酶(POD)的活性及其同工酶.结果表明:紫红色表型盐地碱蓬叶片H2O2含量是绿色表型的2.48倍,而其MDA含量和质膜相对透性却显著低于后者.绿色表型盐地碱蓬POD活性显著高于紫红色表型盐地碱蓬,同工酶分析表明,紫红色表型盐地碱蓬叶片POD同工酶有6条带,即POD1、POD2、POD3、POD4、POD5、POD6,绿色表型盐地碱蓬叶片有5条同工酶条带,为POD1、POD2、POD3、POD4、POD5,POD1是两种表型盐地碱蓬叶片的主要同工酶,占POD总活性的60以上.绿色表型盐地碱蓬叶片POD1、POD2和POD3的活性分别为紫红色表型的1.39倍、4.11倍和3.21倍.这些结果表明,与绿色表型盐地碱蓬相比,紫红色表型盐地碱蓬叶片POD活性低,可能是其叶片积累更高H2O2原因.

Suaeda salsa plants are green （green phenotype） when they grow in saline soil far from the tideland and those are red-violet （red-violet phenotype） when they grow in tideland. In the present study, the leaves of two kinds of phenotype S. salsa are used to examine H2O2 content, MDA content, relative plasma membrane permeability, peroxidase （POD） activity and its isoenzymes. The results show that the H2O2 content in the leaves of red-violet phenotype S. salsa is 2.48 times of that in the green one, while the MDA content and relative plasma membrane permeability are significantly higher than those of the latter. Interestingly, POD activity in the leaves of green phenotype is much higher than that in the leaves of red-violet one. Isoenzyme analysis shows that there are 6 isoforms, i.e. POD1, POD2, POD3, POD4, POD5 and POD6, in the leaves of red-violet one, and only 5 isoforms （POD1, POD2, POD3, POD4 and POD5） are detected in the leaves of green one. Moreover, POD1 is the main form of both phenotypes, which is over 60% of the total activity. Further analysis shows that activity of POD1, POD2 and POD3 in the leaves of green phenotype was 1.39, 4.11 and 3.21 times of that in the red-violet one, respectively. These results suggest that lower POD activity of redviolet phenotype leaves, compared with that of the green one, is one of the reasons for higher H2O2 content in its leaves.