Inhibition of monoterpene biosynthesis accelerates oxidative stress and leads to enhancement of antioxidant defenses in leaves of rubber tree (Hevea brasiliensis)
Inhibition of monoterpene biosynthesis accelerates oxidative stress and leads to enhancement of antioxidant defenses in leaves of rubber tree (Hevea brasiliensis)
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DOI：
10.1007/s11738-008-0205-z
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发表时间：
2009-01-01
影响因子：
2.6
通讯作者：
Cao, Kun-Fang
中科院分区：
文献类型：
--
作者：
Chen, Jun-Wen;Bai, Kun-Dong;Cao, Kun-Fang
本文主要研究了单萜可能的抗氧化作用及其缺失对其他抗氧化防御的影响。橡胶树（Hevea brasiliensis）的叶子通过蒸腾流在黑暗中在室温下用磷咪霉素喂养2小时，然后暴露于明亮的光照（1，500 μ mol m（-2）s（-1））和中等高温（30 ℃）下1小时。结果表明，磷霉素显著抑制了叶片中单萜的生物合成，并使叶片中过氧化氢和丙二醛含量升高。与对照叶片（CK）相比，LFF中的a dagger F/F（m）'在前20 min内显著降低;然而，非光化学猝灭和光合色素（叶绿素和类胡萝卜素）没有显著差异。与此相反，抗氧化酶（超氧化物歧化酶，过氧化氢酶，愈创木酚过氧化物酶，抗坏血酸过氧化物酶，谷胱甘肽还原酶）的活性增强的LFF。同时，LFF中抗氧化代谢产物（抗坏血酸和谷胱甘肽）的含量也高于CK。这些结果表明，单萜在保护植物免受氧化胁迫方面可能是非常有效的分子，单萜的缺失导致酶促和非酶促抗氧化防御对氧化胁迫的反应增强，酶促和非酶促抗氧化防御的增强可能部分地补偿单萜所赋予的抗氧化剂的损失。
This paper mainly studies the possible antioxidant of monoterpene and effects of its absence on other antioxidant defense. The leaves of rubber tree (Hevea brasiliensis) were fed with fosmidomycin through transpiration stream, in the dark, at room temperature for 2 h, and were then exposed to bright illumination (1,500 mu mol m(-2) s(-1)) and moderately high temperature (30A degrees C) for 1 h. The results showed that monoterpene biosynthesis in leaves was considerably inhibited by fosmidomycin, and the elevated levels of both hydrogen peroxide and malondialdehyde were observed in the leaves fed with fosmidomycin (LFF). Compared to the control leaves (CK), a dagger F/F (m)' in the LFF was markedly lower during the first 20 min; however, there were no significant differences in non-photochemical quenching and photosynthetic pigments (chlorophylls and carotenoids). In contrast, the activities of antioxidant enzymes (superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase) were enhanced in the LFF. Meanwhile, the contents of antioxidant metabolites (ascorbate and glutathione) were also elevated in the LFF, when compared with the CK. The results obtained here suggest that monoterpene may be very effective molecule in protecting plants against oxidative stress, the absence of monoterpene leads to the increased responses of the enzymatic and non-enzymatic antioxidant defenses to oxidative stress, and the enhancement of the enzymatic and non-enzymatic antioxidant defenses may, in part, compensate for the loss of antioxidant conferred by monoterpene.