越来越多的研究报告了各种陆地植物的全叶硅浓度，表明不同植物种类的硅 (Si) 积累差异很大。然而，我们对真双子叶植物叶子内各叶部分（例如叶片与叶脉）的硅分布了解有限。在这里，我们报告了两种阔叶树（红枫和直立榕）的叶柄、中脉和叶片中硅积累量随叶龄的变化。我们在每个标记的芽中标记一对相邻的叶子，并在五月和十月收获另一片以测量硅浓度。在这两个物种中，幼叶和老叶中叶片的硅浓度均远高于叶柄和叶脉，并且只有叶片显示出从幼叶到老叶硅浓度明显增加。硅积累率与直立木中的芽大小和叶片产量呈正相关，但与黑脉草中的硅积累率无关。这些结果强烈表明，在双子叶植物物种中，硅主要沉积在叶片中，但在叶柄和叶脉中的含量可以忽略不计，溶解在水中的硅通过叶柄和叶脉运输。未来对双子叶植物中硅积累的生理调控的研究应考虑叶片中的哪些特定细胞负责这种高度局部化的硅沉积。
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Lamina-specific localization of silicon accumulation in two broadleaf tree species
Silicon (Si) accumulation differs greatly among plant species, as revealed by an increasing number of studies reporting whole-leaf Si concentration for a wide range of land plants. Yet, we have limited knowledge about Si distribution across leaf parts (e.g., lamina vs. veins) within a leaf of eudicots. Here, we report how Si accumulation with leaf age differs among petiole, midrib, and lamina in two broad-leaved trees, Acer rufinerve and Ficus erecta. We marked a pair of neighboring leaves in each marked shoot and harvested one in May and the other in October to measure Si concentration. In both species, the lamina showed much higher Si concentration than the petiole and vein in both young and old leaves, and only the lamina showed clear increases in Si concentration from young to old leaves. Si accumulation rate correlated positively with shoot size and leaf production in F. erecta but not in A. rufinerve. These results strongly suggest that, in eudicot species, Si is deposited mostly in leaf lamina but in only a negligible amount in petioles and veins through which Si dissolved in water is transported. Future research on physiological regulations of Si accumulation in eudicot species should consider which specific cells in leaf lamina are responsible for such highly localized Si deposition.