酸铝对不同速生桉无性系叶片抗氧化酶活性的影响

采用砂土培育法,以速生桉优良无性系组培苗(巨尾桉9号、巨尾桉12号、尾叶桉4号、韦赤桉3号)为试验材料,研究酸铝处理下桉树叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)等4种抗氧化酶活性的变化.结果表明:p H是引起抗氧化酶活性变化的主要原因,铝离子的加入进一步影响SOD,POD,PPO活性.4个桉树无性系叶片的POD活性对酸铝胁迫较其他抗氧化酶敏感,变化幅度最大,可以作为判定速生桉耐铝能力强弱的敏感生理指标;SOD和PPO对酸铝胁迫起到一定的抗氧化作用,而CAT没有显著作用;较耐铝的巨尾桉9号和巨尾桉12号叶片POD活性和变幅高于其他两个无性系,耐铝性最强的巨尾桉9号变化最为显著,尾叶桉4号的变化幅度最小;巨尾桉系列的无性系抗氧化酶活性对酸铝胁迫的响应较为灵敏,植株清除活性氧的能力较强.

Effects of Acid-Aluminum on the Activities of Antioxidant Enzymes in the Leaves of Different Fast-growing Eucalyptus Clones

The activities of antioxidant enzymes (SOD,POD,PPO,CAT) in the leaves of four different fast-growing Eucalyptus clones (Eucalyptus grandis × E. urophylla Guanglin No. 9,E. grandis×E. urophylla Guanglin No. 12,E. urophylla Guanglin No. 4,E. urophylla× E. camaldulensis No. 3) were evaluated under acid-aluminum treatments. The results showed that pH value was the main factor to cause the changes of antioxidant enzyme activities and SOD,POD,PPO were further affected by Al3+. The POD activities in Eucalyptus clones were more sensitive than other three enzymes with the biggest variations under the different treatments in four clones,which suggested that POD activity could be considered as a sensitive indicator for assessing Eucaplytus resistance to acid-aluminum stress. SOD and PPO play the certain antioxidation roles while the CAT was insignificant. In the leaves of E. grandis× E. urophylla Guanglin No. 9 and E. grandis× E. urophylla Guanglin No. 12,POD activities were higher than other two clones,especially the most significant change was found in E. grandis× E. urophylla Guanglin No. 9 with best aluninum-tolerance. But the minimal change happened in E. urophylla No. 4. The clones of E. grandis × E. urophylla have stronger abilities to cope with ROS for the activities of antioxidant enzymes responding more sensitively to the acid-aluminum stress.