低温胁迫对喜树幼苗SOD活性、MDA和脯氨酸含量的影响

Effect of Low Temperature Stress on the Membrane-lipid Peroxidation and the Concentration of Free Proline in Camptotheca acuminata Seedling

本文对低温胁迫下喜树幼苗叶片内超氧化物岐化酶 (SOD)活性与叶绿素、游离脯氨酸、丙二醛(MDA)含量的变化进行了研究。结果表明 :喜树幼苗经低温胁迫后叶内叶绿素含量下降 ;SOD活性先下降、后上升、再下降 ,其变化规律不同于其它植物 ;低温造成喜树幼苗的膜脂过氧化 ,MDA含量明显升高 ,SOD活性的增强可以降低MDA的含量 ;脯氨酸随着胁迫的进行其含量升高 ,表明叶内脯氨酸的升高也有助于提高它的抗寒性 ,进一步可以认为叶片内脯氨酸含量的高低可作为衡量喜树抗寒性指标。

The activity of superoxide dismutase (SOD) and the concentration of chlorophyll, free proline (Pro), and malondialdehyde (MDA) of Camptotheca acuminata seedling under low temperature stress were studied. The results are as follows. The low temperature stress (4 ℃ and 8 ℃)decreased the concentration of chlorophyll. The SOD activity became lower at the beginning of stressing and higher later on. After 7 days' stressing, SOD activity became higher comparing to the former phase. This was quite different from other plant's reaction. With the stressing, the concentration of MDA became higher. At the same time, the concentration of Pro was also higher and higher. The results also show that there was a negative relationship between the SOD activity and the concentration of MDA and Pro. The concentration of MDA and Pro can be used as indexes to show how the seedling can endure the cold.