‘次郎’柿成熟叶多酚类物质分布和积累的研究

Distribution patterns of polyphenolic compounds in leaves of Diospyros kaki 'Cilang'

【目的】为了解多酚类物质在‘次郎’柿成熟叶组织和细胞中的分布与积累特点,【方法】根据多酚类物质与锇作用形成稳定螯合物的特性,用四氧化锇处理样品,在光学和电子显微镜下观察。【结果】结果表明,多酚类物质分布于叶片各种组织中,但分布不均匀,上表皮多数细胞充满多酚类物质,下表皮少数细胞含多酚类物质,且含量少;栅栏组织多数细胞含多酚类物质,海绵组织少数细胞含多酚类物质,且含量少;韧皮部和同侧维管束鞘有较多含多酚类物质的细胞,而木质部和同侧维管束鞘基本没有含多酚类物质的细胞;多酚类物质沿液泡膜内表面均匀沉积,在液泡周缘呈一层,或充满液泡。【结论】显然,多酚类物质在"次郞"柿成熟叶中的分布有位置特异性,负责前体转运和加工的装置在液泡膜上密集而均匀地分布。

[Objective] In order to understand the patterns of distribution and accumulation of polyphenolic compounds in leaf blades of Diospyros kaki ＇Cilang＇, [Method] based on the property that phenols react rapidly with osmium tetroxide to produce chelate complexes that display high electron density under the transmission electron microscope, leaf tissues were treated with osmium tetroxide and examined by means of light and electron microscopy. [Result] The deposition of polyphenolics was found in all types of cells, but it occurred unequally among tissues. All adaxial epidermal cells contained polyphenolics that almost took up the whole cell inner space, while only a few abaxial epidermal cells accumulated polyphenolic compounds. All palisade cells contained polyphenolics , whereas most sponge cells did not have polyphenolics. Some phloem parenchyma cells accumulated polyphenolic compounds, but xylem parenchyma cells lacked polyphenolics. Polyphenolic compounds were found in the most cells of phloem and its side bundle sheath, but in the few cells of xylem and its side bundle sheath . Polyphenolic compounds deposited evenly on the whole inner surface of the tonoplast. [Conclusion] It is concluded that polyphenolic accumulation is location-specific and the devices responsible for transportation and modification of phenolic compounds distribute evenly in the tonoplast.