UV screening in higher plants induced by low temperature in the absence of UV-B radiation
UV screening in higher plants induced by low temperature in the absence of UV-B radiation
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DOI：
10.1039/b609820g
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发表时间：
2007-01-01
影响因子：
3.1
通讯作者：
Nybakken, Line
中科院分区：
文献类型：
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作者：
Bilger, Wolfgang;Rolland, Mari;Nybakken, Line
在高等植物中，位于表皮位置的UV-B吸收羟基肉桂酸衍生物和类黄酮类化合物可以作为屏障，抵御潜在的破坏性UV-B(280-315 nm)辐射。我们用叶绿素荧光技术研究了低温对表皮筛选的影响。温室蚕豆植株的表皮紫外线透过率在21~9℃之间强烈依赖于生长温度，在21~18℃之间已有显著差异。表皮UV-A和UV-B吸光度与整个叶提取物在各自波长的吸光度之间具有良好的相关性。然而，在棘豆和长叶酸模中，没有检测到表皮透过率的温度依赖性，而在其他7种作物中，包括夏季和冬季品种，以及拟南芥，都证实了这种温度依赖性。双子叶植物表现出比单子叶植物更强的反应。在所有被调查的物种中，在UV-A光谱区的响应与在UV-B光谱区的响应相似，表明黄酮类化合物是负责的化合物。在蚕豆中，成熟的叶片在从温暖到凉爽的条件下对表皮透光率的变化没有反应，反之亦然，而发育中的叶片确实适应了新的条件。我们得出结论，温度是许多植物表皮紫外线透过率适应环境条件的重要决定因素。讨论了该响应的潜在自适应价值。
Epidermally located UV-B absorbing hydroxycinnamic acid derivatives and flavonoids serve as a screen against potentially damaging UV-B (280 - 315 nm) radiation in higher plants. We investigated the effect of low temperature on epidermal screening as assessed by a chlorophyll fluorescence technique. The epidermal UV-transmittance of greenhouse-grown Vicia faba plants was strongly dependent on growth temperatures between 21 and 9 degrees C, with significant differences already between 21 and 18 degrees C. There was a good correlation between epidermal UV-A and UV-B absorbance and the absorbance of whole leaf extracts at the respective wavelengths. Whereas in Oxyria digyna and Rumex longifolius no temperature dependence of epidermal transmittance could be detected, it was confirmed for seven other crop plant species, including summer and winter varieties, and for Arabidopsis thaliana. Dicotyledoneous plants showed a stronger response than monocotyledoneous ones. In all investigated species, the response in the UV-A spectral region was similar to that in the UV-B, suggesting that flavonoids were the responsible compounds. In V. faba, mature leaves did not respond with a change in epidermal transmittance upon transfer from warm to cool conditions or vice versa, whereas developing leaves did acclimate to the new conditions. We conclude that temperature is an important determinant of the acclimation of epidermal UV transmittance to environmental conditions in many plant species. The potential adaptive value of this response is discussed.