高温胁迫诱导龙牙楤木次生体胚发生过程中抗氧化酶活性变化

摘要

龙牙楤木成熟体胚经37℃高温处理0～3d于不加任何植物生长调节剂的WPM培养基中产生了次生体胚.结果发现,经高温处理1d的外植体的次生体胚发生最好,诱导率为58％,平均每外植体次生体胚约为4个；高温胁迫过程中及次生体胚发生过程中,3种抗氧化酶活性具有明显变化,且处理1d外植体中,3种抗氧化酶活性始终相对较高；高温胁迫使过氧化物酶(POD)、过氧化氢酶(CAT)活性降低,超氧化物歧化酶(SOD)活性则升高.胚性细胞分化期,即成熟体胚分化形成的球形体细胞胚时期(培养10～15 d),POD、SOD活性相对较高,CAT活性较低；次生体胚发育过程中,即发育形成的鱼雷和子叶体细胞胚时期(培养15d以后),SOD、POD活性呈下降趋势,CAT活性则变化不大.%Secondary somatic embryogenesis of Aralia elata (Miq. ) Seem, was induced from the mature somatic embryo under high temperature of 37℃ for 0-3 days and cultured on the WPM medium without any plant growth regulator. The results showed that the treatment of high temperature on mature somatic embryo for 1 day was best for the induction of secondary somatic embryogenesis. The induction frequency was 58% , and the number of somatic embryo per explant was about 4. During the treatments of high temperature and secondary somatic embryogenesis, three anti-oxidative enzymes activities changed obviously, and their activities in the explant treated for 1 day were higher than those in control. Under high temperature stress, the anti-oxidative enzymes of POD and CAT reduced, while the SOD activity increased. At the early period of the embryogenic cell differentiation (cultured for 10-15 days) , the enzymes activities of POD and SOD were higher than those in control, and the enzymes activity of CAT was lower. During the development of secondary somatic embryo (after 15 days) , the enzymes activities of SOD and POD showed reducing trend, however, that of CAT did not change obviously.