ASSOCIATION OF LIPID OXIDATION WITH SEED AGING AND DEATH
ASSOCIATION OF LIPID OXIDATION WITH SEED AGING AND DEATH
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DOI：
10.1038/260323a0
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发表时间：
1976-01-01
期刊：
影响因子：
64.8
通讯作者：
MATTICK, LR
中科院分区：
文献类型：
--
作者：
HARMAN, GE;MATTICK, LR
种子通常在收获后不久就会表现出最大的发芽潜力，随着储存时间的增加，它们会失去活力并最终死亡。生理老化速度通常随着水分含量和温度的增加而增加1。此外，当种子含水量与相对湿度大于 65% 达到平衡时，某些旱生储藏真菌（主要是曲霉属）会攻击储藏中的种子（参考文献 1），并引起模拟生理老化的变化。伴随生理老化1-5和储藏真菌5侵袭的生理变化已被编录，但导致这些变化的基本生化事件尚不清楚。然而，Harrington1 和 Pammenteret al.6 提出，不饱和脂质的氧化可能导致自由基的形成。然后自由基可能会损害细胞膜并与大分子发生破坏性反应。类似的建议也被提出来解释其他几个系统中的老化7，这里报告的实验结果表明自由基的形成可能在种子变质中很重要。脂质氧化机制的理论表明，具有两个或多个不饱和键的脂肪酸应该比高度饱和的酸更不稳定并且更容易形成自由基8,9。因此，如果发生脂肪酸氧化和自由基形成，随着种子变质，高度不饱和酸应该减少，而在没有β氧化的情况下，饱和脂肪的数量应该保持恒定。
SEEDS usually exhibit their maximum germination potential soon after harvest, and as storage time increases, they lose vigour and eventually die. The rate of physiological ageing generally increases with increased moisture content and temperature1. In addition, certain xerophytic storage fungi (primarilyAspergillusspp.) can attack seeds in storage when seed moisture content is in equilibrium with relative humidities greater than 65% (ref. 1), and cause changes that mimic physiological ageing. Physiological changes accompanying physiological ageing1–5and attack by storage fungi5have been catalogued, but the basic biochemical events leading to these changes are not known. Harrington1and Pammenteret al.6, however, have suggested that oxidation of unsaturated lipids may lead to free-radical formation. Free radicals may then damage cellular membranes and react destructively with macromolecules. Similar suggestions have been presented to explain ageing in several other systems7, and the results of experiments reported here indicate that free-radical formation may be important in seed deterioration. Theories of mechanisms of lipid oxidation indicate that fatty acids with two or more unsaturated bonds should be more labile and prone to form free radicals than more highly saturated acids8,9. Thus, if fatty acid oxidation and free-radical formation are occurring, the highly unsaturated acids should decrease as seeds deteriorate, whereas the quantity of saturated fats should remain constant in the absence of beta oxidation.