Laboratory of Electron Microscopy, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland.
Protoplasma. 2013 Apr;250(2):601-11. doi: 10.1007/s00709-012-0445-z. Epub 2012 Aug 16.
The positive influence of anthocyanin (ATH) on toxic metal-treated plant material is well documented; however, it is still not explained if it is caused by changes in element absorption and distribution. Therefore, detailed analysis of the effect of the ATH-rich extract from red cabbage leaves on Pb uptake and localization at morphological, anatomical and ultrastructural level was the goal of this study. Two-day-old adventitious roots of Allium cepa L. (cv. Polanowska) were treated for 2 h with the aqueous solution of Pb(NO3)2 at the concentration of 100 μM with or without preliminary incubation in the anthocyanin-rich extract from Brassica oleracea L. var. capitata rubra leaves (250 μM, 3 h). The red cabbage extract did not change the total Pb uptake but it enhanced the translocation of accumulated metal from roots to shoots. Within the pretreated roots, more Pb was deposited in their basal part and definitely smaller amount of the metal was bound in the apoplast of the outer layers of cortex cells. The ultrastructural analysis (transmission electron microscopy and X-ray microanalysis) revealed that the ATH-rich extract lowered the number of Pb deposits in intracellular spaces, cell wall and cytoplasm of root meristematic cells as well as in such organelles important to cell metabolism as mitochondria, plastids and nucleus. The Pb deposits were preferably localised in those vacuoles where ATH also occurred. This sequestration of Pb in vacuoles is probably responsible for reduction of metal cytotoxicity and consequently could lead to better plant growth.
花色素苷（ATH）对受有毒金属处理的植物材料的积极影响已有充分的文献记载；然而，其是否是由于元素吸收和分布的变化引起的，目前仍未得到解释。因此，本研究的目的是详细分析富含花色素苷的红甘蓝叶提取物对 Pb 吸收和定位的影响，包括形态学、解剖学和超微结构水平。用浓度为 100μM 的 Pb(NO3)2 水溶液处理洋葱（cv. Polanowska）2 天大的不定根 2 小时，同时或不预先在富含花色素苷的红甘蓝叶提取物（250μM，3 小时）中孵育。红甘蓝提取物并没有改变总 Pb 吸收量，但增强了金属从根部向地上部的转运。在预处理的根中，更多的 Pb 沉积在根的基部，而金属在皮层细胞外层质外体中结合的量明显减少。超微结构分析（透射电子显微镜和 X 射线微分析）表明，富含花色素苷的提取物减少了根分生细胞的细胞内空间、细胞壁和细胞质以及对细胞代谢很重要的细胞器（如线粒体、质体和细胞核）中 Pb 沉积物的数量。Pb 沉积物主要位于 ATH 也存在的那些液泡中。Pb 在液泡中的这种隔离可能是降低金属细胞毒性的原因，从而导致更好的植物生长。
