Surface Structures and Chemical Composition of Epicuticular Waxes during Leaf Development of Fagus sylvatica L.
Surface Structures and Chemical Composition of Epicuticular Waxes during Leaf Development of Fagus sylvatica L.
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水青冈叶片发育过程中表皮蜡质的表面结构和化学成分。
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
E. Müller
中科院分区：
文献类型：
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作者：
Paul;R. Prasad;E. Müller
摘要 采用扫描电镜研究了山毛榉 (Fagus sylvatica) 叶蜡的表面结构，并将其与一个生长期提取的蜡脂的化学成分相关联。刚刚从芽中展开的非常年轻的小叶已经含有蜡层，没有任何蜡雕或晶体。该蜡层的产量和成分与成熟叶子的蜡层有很大不同。随着山毛榉叶子的展开，几种蜡脂的动态生物合成开始，但蜡酯的生物合成没有进一步继续。叶子展开十天后，首次检测到醛的从头生物合成。醛量迅速增加至蜡的约13%。合成的主要蜡脂分别是具有 C28 链长的醛、醇和脂肪酸以及具有 C27 链长的烃。山毛榉叶中蜡脂的生物合成于五月底完成，并且在剩余季节中数量和成分几乎保持恒定。在首次发现醛的同时，在山毛榉叶蜡上观察到从连续蜡层中出来的蜡雕，仅在叶的上侧。这些蜡雕在接下来的时间里尺寸和数量不断增加，并且整个季节都出现在叶面的上部，只有一些蜡雕表现出结晶形式的趋势。
Abstract The surface structures of beech ( Fagus sylvatica) leaf waxes were studied by SEM and correlated with chemical compositions of the extracted wax lipids during one vegetation period. The very young leaflets just unfolding from buds contained already a wax layer without any wax sculptures or crystalloids. This wax layer is quite different in yield and composition to that of mature leaves. With the unfolding of beech leaves, a dynamic biosynthesis of several wax lipids was started, but the biosynthesis of wax esters was not continued further. Ten days after leaf unfolding the de novo biosynthesis of aldehydes could be detected for the first time. Aldehyde amount increased rapidly to about 13% of the wax. The predominant individual wax lipids synthesized were aldehydes, alcohols and fatty acids with C28 and hydrocarbons with C27 chain lengths, respectively. The biosynthesis of wax lipids in beech leaves was completed at the end of May and remained nearly constant in quantity and com position during the remaining season. At the same time when aldehydes were found for the first time, wax sculptures were observed on beech leaf waxes coming out of the continuous wax layer, exclusively on the upper leaf side. These wax sculptures increased in size and quantity in the following time and were present on the upper leaf side all over the season, only some wax sculptures show a trend to crystalline forms.