Inter- and intraspecific structural variations among intervascular pit membranes, as revealed by field-emission scanning electron microscopy.
Inter- and intraspecific structural variations among intervascular pit membranes, as revealed by field-emission scanning electron microscopy.
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DOI：
10.3732/ajb.92.7.1077
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发表时间：
2005-07
影响因子：
3
通讯作者：
Y. Sano
中科院分区：
文献类型：
--
作者：
Y. Sano
采用场发射扫描电镜对四种双子叶植物（沙柳、白桦、槭和水曲柳）的维管间坑膜结构进行了研究。mandwaterica var. japonica的维管间坑膜表层较薄，中间层较密，而其他3种都没有类似的中间层。在水曲花中，每个坑膜的整个区域被微原纤维密集覆盖。相比之下，在其他三个物种中，在坑膜上发现了开口。在sachalinensis、B. platyphylla vara . japonica和A. mono的一些维管间坑膜中，微原纤维稀疏地交织在坑膜的小区域，在这些区域存在直径达几百纳米的开口。这些多孔区域往往位于坑膜的外围区域。在sachalinensis和B. platyphylla ar. japonica中，大量的醇溶性提取物分布在维管间坑膜上，其化学性质和功能尚不清楚。我们的观察表明，血管间窝膜的结构比以前认识到的要复杂得多。
The structure of the intervascular pit membranes of four dicotyledonous species (Salix sachalinensis, Betula platyphylla var. japonica, Acer mono, and Fraxinus mandshurica var. japonica) was examined by field-emission scanning electron microscopy. The intervascular pit membranes of F. mandshurica var. japonica had thin surface layers and a dense middle layer, while no similar middle layer was detectable in the other three species. In F. mandshurica var. japonica, the entire area of each pit membrane was densely covered with microfibrils. In the other three species, by contrast, openings were found in the pit membranes. In some of the intervascular pit membranes of S. sachalinensis, B. platyphylla var. japonica, and A. mono, microfibrils were sparsely interwoven in small areas of the pit membranes and openings of up to several hundred nanometers in diameter were present in such regions. These porous regions tended to be located in peripheral areas of pit membranes. In S. sachalinensis and B. platyphylla var. japonica, ethanol-soluble extracts, whose chemical nature and function remain unknown, were heavily distributed over the intervascular pit membranes. Our observations suggest that the structure of intervascular pit membranes is more complicated than has previously been acknowledged.