Protective effect of melatonin against chlorophyll degradation during the senescence of barley leaves
Protective effect of melatonin against chlorophyll degradation during the senescence of barley leaves
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DOI：
10.1111/j.1600-079x.2008.00625.x
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发表时间：
2009-01-01
影响因子：
10.3
通讯作者：
Hernandez-Ruiz, J.
中科院分区：
文献类型：
--
作者：
Arnao, M. B.;Hernandez-Ruiz, J.
褪黑激素（N-乙酰基-5-甲氧基色胺）是一种高度保守的分子，其存在并非动物界所独有。事实上，许多研究已经证明了它在植物中的存在，其中这种吲哚胺的可能作用正在积极调查中。目前的工作旨在进一步我们在这方面的知识，并提出了褪黑激素对叶片衰老的影响的研究结果。用褪黑激素溶液处理的大麦叶片明显减缓了衰老过程，这是从叶片中叶绿素的损失来估计的。褪黑激素的这种作用是浓度依赖性的，在黑暗中孵育48小时后，在1 mm褪黑激素下获得最佳响应。植物激素、激动素和脱落酸的已知作用也进行了测定。在测定的植物激素和褪黑激素的组合中，1 mm褪黑激素呈现最好的抗衰老保护。通过具有荧光检测的液相色谱法测量对照叶片中的内源褪黑激素水平，以及用不同外源褪黑激素浓度处理的叶片中的内源褪黑激素水平（以证明叶片的吸收能力）。这一新发现的褪黑激素在叶片衰老的行动可能的生理影响进行了讨论。
Melatonin (N-acetyl-5-methoxytryptamine) is a highly conserved molecule whose presence is not exclusive to the animal kingdom. Indeed, numerous studies have demonstrated its presence in plants, where the possible role(s) of this indoleamine is (are) under active investigation. The present work aims to further our knowledge in this respect and presents the results of a study of the effect that melatonin has on foliar senescence. Barley leaves treated with melatonin solutions clearly slowed down the senescence process, as estimated from the chlorophyll lost in leaves. This effect of melatonin was concentration dependent, with an optimal response being obtained at 1 mm melatonin, after 48 hr of incubation in darkness. The already known effects of the phytohormones, kinetin, and abscisic acid, were also assayed. Of the phytohormone and melatonin combinations assayed, 1 mm melatonin presented the best protection against senescence. The levels of endogenous melatonin in control leaves were measured by liquid chromatography with fluorescence detection and in leaves treated with different exogenous melatonin concentrations (to demonstrate the absorption capacity of leaves). The possible physiological implications of this newly revealed action of melatonin in foliar senescence are discussed.