BIOCHEMICAL HETEROPHYLLY AND FLAVONOID EVOLUTION IN NORTH-AMERICAN POTAMOGETON (POTAMOGETONACEAE)
BIOCHEMICAL HETEROPHYLLY AND FLAVONOID EVOLUTION IN NORTH-AMERICAN POTAMOGETON (POTAMOGETONACEAE)
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DOI：
10.2307/2444379
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发表时间：
1990-04-01
影响因子：
3
通讯作者：
SHERIDAN, DJ
中科院分区：
文献类型：
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作者：
LES, DH;SHERIDAN, DJ
形态学上的异叶物种眼子菜也通常显示生化异叶相对于黄酮类化合物。一般来说，漂浮的叶子含有各种各样的类黄酮，而淹没的叶子通常表现出减少的类黄酮特征。在严格沉水（同源）的物种，两种模式发生。线性叶的物种有几个黄酮类化合物和他们的生化配置文件类似的淹没叶的异叶物种。同叶阔叶树种的类黄酮含量与异叶阔叶树种的浮叶更相似。这些化学数据的数值分析是一致的属内的形态和染色体数据的基础上独立得出的系统发育关系。黄酮类化合物由于其对紫外线的过滤能力而可能存在于漂浮的叶片中，在眼子菜中表现出最明显的生化异质性。异叶物种的沉水叶和线形叶的同源物种中缺乏糖苷类黄酮是由于天然有色水显著吸收有害紫外线辐射的能力。这些观察结果为早期的假设提供了强有力的支持，这些假设表明类黄酮进化在植物征服暴露的陆地栖息地中的重要性。
Morphologically heterophyllous species of Potamogeton also commonly display biochemical heterophylly with respect to flavonoid compounds. Generally, floating leaves contain as assortment of flavonoids, whereas submersed leaves often exhibit reduced flavonoid profiles. In strictly submerged (homophyllous) species, two patterns occur. Linear-leaved species have few flavonoids and their biochemical profiles resemble those of submersed leaves of heterophyllous species. Broad-leaved homophyllous species possess flavonoid profiles more similar to those of the floating leaves of heterophyllous species. Numerical analysis of these chemical data is consistent with phylogenetic relationships within the genus derived independently on the basis of morphological and chromosomal data. Glycoflavones, which are probably maintained in floating leaves because of their UV filtering ability, exhibit the most pronounced biochemical heterophylly in Potamogeton. The lack of glycoflavones in submerged leaves of heterophyllous species and in linear-leaved homophyllous species is attributable to the ability of naturally colored water to significantly absorb harmful UV radiation. These observations provide strong support for earlier hypotheses suggesting the importance of flavonoid evolution in the conquest of exposed terrestrial habitats by plants.