外源亚精胺对黄果柑果实抗氧化酶活性的影响

为探索亚精胺(spermidine,Spd)与3种抗氧化酶过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性变化的关系,以及黄果柑果实成熟过程中抗氧化酶活性的变化趋势。以5 a生黄果柑果树为实验材料,设置3个不同质量浓度的亚精胺处理,通过叶面、果面喷施亚精胺,研究外源亚精胺对黄果柑果实发育后期抗氧化酶活性的影响。结果表明:外源Spd能显著提高黄果柑果实中Spd和精胺含量,极显著降低腐胺含量;显著提高黄果柑果实转色初期CAT、POD和SOD活性;显著降低成熟后果实丙二醛(malondialdehyde,MDA)含量,推迟MDA含量快速累积的时间。结果显示,外源Spd具有改善黄果柑果实抗氧化保护系统的功能,通过调控黄果柑果实抗氧化酶活性,提高自由基防御系统的防御能力。

Effects of Exogenous Spermidine on Activities of Antioxidant Enzymes in ‘Huangguogan’ Orange Fruits

This study was conceived to explore the relationship between exogenous spermidine (Spd) and the activities
of antioxidant enzymes, namely catalase (CAT), peroxidases (POD) and superoxide dismutase (SOD) and investigate the
changes in these antioxidant enzyme activities during the ripening process of oranges. The leaves and fruits of five-yearold
‘Huangguogan’ orange trees were sprayed with spermidine at three concentrations to examine the effect of exogenous
Spd on the antioxidant enzyme activities during the later developmental stage. The results showed that exogenous Spd
could significantly improve the contents of Spd and spermine (Spm) and significantly decrease the content of Put. During
the early color-turning period, exogenous Spd treatment caused significant increases in the activities of CAT, POD and SOD
and a significant decrease in malondialdehyde (MDA) content in the ripe fruits, and retarded the rapid accumulation of
MDA. These findings suggest that exogenous Spd can improve the antioxidant defense system in ‘Huangguogan’ fruits by
enhancing the activities of CAT, POD and SOD.