Companion-Cell Specific Localization of Sucrose Synthase in Zones of Phloem Loading and Unloading

摘要: An immunohistochemical approach was used in maize (Zea mays) and citrus (Citrus paradisi) to address the previously noted association between sucrose synthase vascular bundles determine localization of low but detectable levels that remain leaves after import-export transition. Sucrose protein immunolocalized at light microscope level using paraffin sections reacted with rabbit polyclonal antisera gold-conjugated goat anti-rabbit immunoglobulin G. Immunolabel specifically observed phloem companion cells minor intermediate veins mature both species. Similar apparent midrib leaves, additional labeling selected files parenchyma cells. A clear companion-cell specificity evident unloading zone fruit, where high activity has been demonstrated during periods rapid import. not associated adjacent surrounding strands this tissue. The importing exporting structures these diverse species implies may be a widespread underscores its potential importance physiology bundles.