缺氧及氧恢复对马铃薯块茎线粒体中活性氧及抗氧化酶的影响

Effects of Anoxia and Post-Anoxia on Reactive Oxygen Species(ROS) and Antioxidant Enzymes in Tuber Mitochondria of Potato(Solanum tuberosum L.)

选用马铃薯‘Favorita’品种,采用淹水及淹水后恢复通气的方法,研究了缺氧及氧恢复条件对马铃薯块茎亚细胞水平线粒体中活性氧(ROS)及抗氧化酶的影响。结果表明:缺氧胁迫会导致块茎线粒体中超氧阴离子(O2ˉ·)的发生速率、过氧化氢(H2O2)及丙二醛(MDA)的含量先升高后下降,其中在缺氧第1天时分别比对照升高43.95%、49.18%、69.20%,在缺氧第3天时各项指标均达到最大值;而缺氧胁迫下超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)活性呈现先降低、后升高、再降低的趋势,其中缺氧第1天分别比对照降低28.35%、31.48%、37.36%。氧恢复时O2ˉ·发生速率,H2O2及MDA含量,SOD、APX、CAT的活性同样呈现先升高后降低的趋势,其中与缺氧1 d未恢复对照相比,氧恢复1 d分别提高144.69%、63.45%、59.07%、39.29%、11.45%、2.88%。另外,上述各项指标因缺氧胁迫与氧恢复时间的不同而有较大的变化。由此推测:氧恢复比缺氧胁迫更能促进马铃薯块茎线粒体ROS的爆发,加剧膜脂过氧化,并增强线粒体抗氧化酶的短时防御性能。

With the methods of waterlogging and subsequent recovery, different responses of reactive oxygen species （ROS） and antioxidant enzymes at the subcellular level of potato （Solanum tuberosum cv. ＇Favorita＇） tuber mitochondria to anoxia and post-anoxia were investigated. The results showed that the superoxide anion （07） generating rate, the contents of hydrogen peroxide （H202） and malondialdehyde （MDA） in tuber mitochondria under anoxia raised at first and then declined, increased by 43.95%, 49.18% and 69.20% respectively at the first day of anoxia compared with the control, and reached the maximum at the third day. Meanwhile the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX） and catalase （CAT） of tuber mitochondria presented the trend of declining-rising-declining, and decreased by 28.35%, 31.48% and 37.36% respectively at the first day of anoxia compared with the control. Similarly, the O^- generating rate, the contents of H202 and MDA, and the activities of SOD, APX and CAT in tuber mitochondria under post-anoxia also increased first and then decreased, and increased by 144.69%, 63.45%, 59.07%, 39.29%, 11.45% and 2.88% respectively for one-day post-anoxia compared with the one-day anoxia. Moreover, the above indexes showed a relatively large change for the different treatment time of anoxic stress and post-anoxia. Above all, the ROS in tuber mitochondria was easier to burst and aggravate the membrane lipid peroxidation under post- anoxia than anoxic stress. As a result, the short-term defensive abilities of mitochondrial antioxidant enzymes were enhanced.