Endogenous Hydrogen Peroxide Plays a Positive Role in the Upregulation of Heme Oxygenase and Acclimation to Oxidative Stress in Wheat Seedling Leaves
Endogenous Hydrogen Peroxide Plays a Positive Role in the Upregulation of Heme Oxygenase and Acclimation to Oxidative Stress in Wheat Seedling Leaves
复制标题
内源过氧化氢在小麦幼苗叶片血红素加氧酶的上调和氧化应激适应中发挥积极作用
DOI：
10.1111/j.1744-7909.2009.00869.x
复制
发表时间：
2009-10-01
影响因子：
11.4
通讯作者：
Shen, Wen-Biao
中科院分区：
文献类型：
--
作者：
Chen, Xiao-Yue;Ding, Xiao;Shen, Wen-Biao
预处理较低的H2 O2剂量（0.05，0.5和5 mM）为24小时能够剂量依赖性地减弱小麦幼苗叶片脂质过氧化反应介导的进一步氧化损伤引起的更高剂量的H2 O2（150 mM）为6小时，与0.5 mM H2 O2是最有效的浓度。进一步的结果表明，0.5 mM H2 O2预处理触发的两相生产H2 O2在24小时内。我们还注意到，只有峰I（0.25 h）而不是峰II（4 h）与血红素加氧酶（HO）活性、HO-1基因表达的增强大致一致。同时，超氧化物歧化酶（SOD）活性、Mn-SOD和Cu，Zn-SOD转录本的增强可能是内源H2 O2峰值I的潜在来源。进一步的结果证实，0.5 mM H2 O2处理0.5 h能够上调HO基因的表达，这是通过酶活性测定，半定量逆转录-聚合酶链反应和蛋白质印迹检测。同时，N，N '-二甲基硫脲作为内源性H2 O2的捕获剂，不仅阻断了HO的上调，而且逆转了相应的氧化衰减。总之，上述结果表明，内源性H2 O2的产生（峰I）在HO的诱导中起着积极的作用，通过提高其mRNA水平和蛋白质表达，从而导致对氧化应激的适应。
Pretreatment of lower H2O2 doses (0.05, 0.5 and 5 mM) for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 (150 mM) for 6 h, with 0.5 mM H2O2 being the most effective concentrations. Further results illustrated that 0.5 mM H2O2 pretreatment triggered the biphasic production of H2O2 during a 24 h period. We also noticed that only peak I (0.25 h) rather than peak II (4 h) was approximately consistent with the enhancement of heme oxygenase (HO) activity, HO-1 gene expression. Meanwhile, enhanced superoxide dismutase (SOD) activity, Mn-SOD and Cu,Zn-SOD transcripts might be a potential source of peak I of endogenous H2O2. Further results confirmed that 0.5 mM H2O2 treatment for 0.5 h was able to upregulate HO gene expression, which was detected by enzyme activity determination, semi-quantitative reverse transcription-polymerase chain reaction and western blotting. Meanwhile, the application of N,N'-dimethylthiourea, a trap for endogenous H2O2, not only blocked the upregulation of HO, but also reversed the corresponding oxidation attenuation. Together, the above results suggest that endogenous H2O2 production (peak I) plays a positive role in the induction of HO by enhancing its mRNA level and protein expression, thus leading to the acclimation to oxidative stress.