Philpott Martin, Ferguson Lynnette R, Gould Kevin S, Harris Philip J
Discipline of Nutrition, Faculty of Medical & Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
J Plant Physiol. 2009 Jul 1;166(10):1112-7. doi: 10.1016/j.jplph.2008.12.007. Epub 2009 Feb 6.
Anthocyanins, which are O-glycosylated derivatives of anthocyanidins, are responsible for the red, blue and purple coloration of many organs of angiosperms where they have previously been reported to occur in vacuoles and cytoplasm. However, bright-field microscopy of sections of the storage roots of the sweet potato (Ipomoea batatas) clone 99N1/222, which contains high concentrations of anthocyanins, showed that the walls of the periderm cork cells (skin), but not those of the adjacent parenchyma cells, were coloured bright red/purple. In situ absorption spectra of the periderm cell walls were similar to those of methanolic solutions of anthocyanins. Dry cell-wall preparations obtained from the periderm and parenchyma tissues were coloured deep reddish-brown and white, respectively. Pigment was extracted from the periderm cell-wall preparation by treating with 1 M NaOH. Acid hydrolysis of this extract followed by HPLC indicated the presence of the anthocyanidins cyanidin and peonidin. It is concluded that the periderm cell walls contain covalently bound anthocyanidin-containing compounds, possibly anthocyanins.
花青素是花色素苷的O-糖基化衍生物，它们赋予被子植物许多器官红色、蓝色和紫色，此前据报道它们存在于液泡和细胞质中。然而，对含有高浓度花青素的甘薯（Ipomoea batatas）克隆99N1/222的贮藏根切片进行明场显微镜观察发现，周皮木栓细胞（表皮）的细胞壁呈现亮红色/紫色，而相邻薄壁细胞的细胞壁则没有。周皮细胞壁的原位吸收光谱与花青素甲醇溶液的吸收光谱相似。从周皮和薄壁组织获得的干细胞壁制剂分别呈深红褐色和白色。通过用1 M NaOH处理从周皮细胞壁制剂中提取色素。对该提取物进行酸水解，然后进行HPLC分析，结果表明存在花色素苷矢车菊素和芍药色素。结论是周皮细胞壁含有共价结合的含花色素苷化合物，可能是花青素。
