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1080 生态环境学报 第 19 卷第 5 期(2010 年 5 月)
SO2 胁迫响应中起着重要作用。
SO2 胁迫处理过程中, 139 和昌 7-2 叶片 CAT
齐
的活性变化差异显著(图 4-B)。高抗性齐 139 叶
片 CAT 的活性表现明显的上升趋势,在胁迫处理
前 6 h 缓慢升高,12 h 达到最大,然后急剧下降,
24 h 时趋于起始状态;而在高感系昌 7-2 叶片中,
胁迫早期 6 h CAT 的活性缓慢升高,12 h 后急剧下
降,24 h 时活性明显低于对照,暗示了敏感系中抗
氧化防护酶 CAT 在胁迫处理 12 h 后已受到损伤,
活性显著低于对照。
(A) 齐139-CK 齐139-T R
200 昌7-2-CK 昌7-2-T R
齐139-CK 齐139-T R
0.6
SOD 活性/(U g-1 FW)
昌7-2-CK 昌7-2-T R
160
0.5
120
0.4
H2 O2 含量/ (µmol g-1 )
0.3 80
0.2 40
0 3 6 12 24
0.1 t (处理)/h
(A)
0
0 3 6 12
t (处理)/h 6 齐139-CK 齐139-T R
昌7-2-CK 昌7-2-T R
(B)
5
CAT 活性/(µmol min-1 g-1 )
(A)联苯胺染色检测高抗系(齐 139)和高感系(昌 7-2)叶
片 H2O2 的产生;(B)定量测定高抗系(齐 139)和高感系(昌 7-2) 4
叶片 H2O2 的产生。CK:对照 control;TR:treatment.
3
图3 SO2 胁迫下玉米抗感自交系叶片 H2O2 产生的动态变化
Fig.3 Dynamic change of H2O2 production in tolerant and susceptible 2
maize inbred lines under SO2 stress
1
0
高峰,随后开始降低;而高感系昌 7-2 在处理 12 h
0 3 6 12 24
后一直保持较高的活性氧积累,这可能是其对 SO2 t (处理)/h
较敏感受伤害较重的原因之一。 (B)
2.4 SO2 胁迫对抗感玉米幼苗叶片活性氧代谢关 图 4 SO2 胁迫下玉米抗感自交系叶片 SOD 和 CAT 活性的动态变化
键酶的影响 Fig.4 Dynamic changes of SOD and CAT activities in tolerant
SOD 和 CAT 作为主要的活性氧代谢酶,对于 and susceptible maize inbred lines under SO2 stress
维持植物体内 ROS 动态平衡起着主导作用。 SO2对
胁迫下抗感材料中 SOD 和 CAT 活性的动态变化分 3 讨论
析表明: 2 胁迫过程中, 139 和昌 7-2 叶片 SOD
SO 齐 植物在胁迫条件下会发生氧化胁迫,促使活性
的活性变化差异显著(图 4-A)。高抗性齐 139 叶 氧物质(ROS)如超氧阴离子自由基(O2-)和过氧化
片 SOD 的活性呈现明显的上升趋势,在胁迫早期 氢(H2O2)等的产生及过量累积而损伤细胞。本实验
逐渐升高,12 h 达到最大,然后急剧下降,24 h 时 通过对抗感玉米自交系在SO2胁迫下活性氧代谢的
趋于起始状态;而在高感系昌 7-2 叶片中,胁迫早 差异的比较,发现抗性系在胁迫早期(3 h)产生较
期 SOD 的活性缓慢升高,12 h 后急剧下降,24 h 多的活性氧(O2-和H2O2),随后开始降低并趋于平
时活性低于对照,说明其 SOD 受到严重损伤。这 衡,而敏感性在胁迫早期产生的活性氧较少,后期
一结果暗示了抗氧化防护酶 SOD 在玉米幼苗对 (12 h)有大量的活性氧积累。与此趋势对应,抗性
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夏宗良等:二氧化硫胁迫对不同抗性玉米幼苗活性氧代谢的影响 1081
系在胁迫处理的12 h后抗氧化酶SOD和CAT活性最 参考文献:
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Effects of sulfur dioxide stress on reactive oxygen species metabolism
of maize seedlings with contrasting tolerance
XIA Zongliang, XUE Ruili, WU Ke, ZHOU Peng, WU Jianyu
College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
Abstract: Differences in reactive oxygen species (ROS) metabolism were analyzed in maize(Zea Mays. L) seedlings from highly
tolerant inbred Qi139 and highly sensitive inbred Chang7-2 by 60 mg·m-3 SO2 treatment. The results showed that in the tolerant line
Qi139 a significant increase in the production of O2– and H2O2 occurred within the first 3 h of treatment; subsequently, the increased
ROS were rapidly scavenged and reached the balance states at 12 h of the stress. On the contrary, in the sensitive line chang7-2 a less
increase in the production of O2– and H2O2 was observed within the first 3 h of treatment, and the ROS production was increased
rapidly after 12 h of the stress, which caused oxidative damage to cells. The activities of the main antioxidant enzymes Superoxide
dismutase (SOD) and catalase (CAT) in the tolerant inbred were up-regulated significantly, but not in the sensitive inbred seedlings.
This study suggests that the differences in active oxygen species metabolism among maize inbred lines with different sensitivities
may be closely relevant to SO2 tolerance.
Key words: maize; sulfur dioxide; reactive oxygen species; stress; antioxidant enzymes
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