Melatonin in Glycyrrhiza uralensis:: response of plant roots to spectral quality of light and UV-B radiation
Melatonin in Glycyrrhiza uralensis:: response of plant roots to spectral quality of light and UV-B radiation
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DOI：
10.1111/j.1600-079x.2006.00337.x
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发表时间：
2006-09-01
影响因子：
10.3
通讯作者：
Kozai, T.
中科院分区：
文献类型：
--
作者：
Afreen, F.;Zobayed, S. M. A.;Kozai, T.
褪黑素（n -乙酰-5-甲氧基色胺）是由脊椎动物的松果体合成和分泌的。研究了乌拉甘草（Glycyrrhiza uralensis）根中褪黑素存在的证据，以及该植物对红、蓝、白光（对照）和UV-B辐射（280 ~ 315 nm）光谱质量合成褪黑素的反应。从种子、根、叶和茎组织中提取褪黑素并进行定量分析，结果表明根组织中褪黑素含量最高；褪黑素浓度也随着植物发育而增加。在红色、蓝色和白色荧光灯下生长3个月后，暴露在红光下的植物褪黑素浓度最高，褪黑素浓度随光谱波长的变化顺序为：红>蓝>=白光。有趣的是，在更成熟的植物（6个月）中，褪黑激素浓度显著增加；6月龄红、蓝、白光暴露（对照）植株的浓度增量分别为X4、X5和X3。暴露在蓝光和白光下的植物（对照）褪黑素浓度差异不显著。在高强度UV-B照射3天后，植物根组织中褪黑素的定量浓度最高，随后在低强度UV-B照射15天。在较长时间的UV-B照射下褪黑素的减少表明褪黑素的合成可能与UV-B照射的综合（强度和持续时间）值有关。乌拉尔草中的褪黑素可能是为了防止紫外线照射引起的氧化损伤。
Melatonin (N-acetyl-5-methoxytryptamine) is known to be synthesized and secreted by the pineal gland in vertebrates. Evidence for the occurrence of melatonin in the roots of Glycyrrhiza uralensis plants and the response of this plant to the spectral quality of light including red, blue and white light (control) and UV-B radiation (280-315 nm) for the synthesis of melatonin were investigated. Melatonin was extracted and quantified in seed, root, leaf and stem tissues and results revealed that the root tissues contained the highest concentration of melatonin; melatonin concentrations also increased with plant development. After 3 months of growth under red, blue and white fluorescent lamps, the melatonin concentrations were highest in red light exposed plants and varied depending on the wavelength of light spectrum in the following order red > blue >= white light. Interestingly, in a more mature plant (6 months) melatonin concentration was increased considerably; the increments in concentration were X4, X5 and X3 in 6-month-old red, blue and white light exposed (control) plants, respectively. The difference in melatonin concentrations between blue and white light exposed (control) plants was not significant. The concentration of melatonin quantified in the root tissues was highest in the plants exposed to high intensity UV-B radiation for 3 days followed by low intensity UV-B radiation for 15 days. The reduction of melatonin under longer periods of UV-B exposure indicates that melatonin synthesis may be related to the integrated (intensity and duration) value of UV-B irradiation. Melatonin in G. uralensis plant is presumably for protection against oxidative damage caused as a response to UV irradiation.