| The early bulking period, the rapid enlargement period, the coloring period and the maturation period leaf of Ziziphus jujuba Mill cv. Lingwuchangzao were used as experimental material to study the distribution of arabinogalactan proteins AGPs using methods of immunofluorescence localization in different development periods. The results showed that the external tangential cell walls of leaf epidermis cells in different developmental stages were all quite thick, antigen fluorescence of AGPs recognized by antibody distributed copiously, and formed fairly thick cuticles. The cell walls perpendicular to leaf blade were quite thin, antigen fluorescence of AGPs recognized by antibody distributed sparsely, stomatal guard cells of lower epidermis distributed a few AGPs. The mesophyll consisted entirely of developed palisade tissue cells, the cell walls and cell interiors of the mesophyll distributed densely antigen fluorescence of AGPs recognized by antibody in different periods leaf, the mesophyll was the main tissue of leaf AGPs distribution. The cell walls and cell interiors of xylem, phloem, and cambium of vascular bundles in main veins distributed mass antigen fluorescence of AGPs recognized by antibody, but AGPs of main veins in the rapid enlargement period decreased slightly compared with other periods. However, the cell walls and cell interiors of xylem and phloem of vascular bundles in lateral veins and veinlets located in the mesophyll distributed all along mass antigen fluorescence of AGPs recognized by antibody. There was no antigen fluorescence of AGPs recognized by antibody in the vascular bundle sheaths of main veins, lateral veins and veinlets, which might be related to the formation of secretions in the vascular bundle sheaths. Mechanical tissues and parenchyma cell walls beneath the epidermis located at main veins and lateral veins distributed much antigen fluorescence of AGPs recognized by antibody, with no distribution in the secretory ducts located at parenchyma. All the results above indicated that there were some differences in fluorescence intensity of antigen recognized by antibody in different leaf tissues, AGPs distributed copiously in the external tangential cell walls of leaf epidermis cells in different developmental stages, and leaf epidermis formed quite thick cuticles. The mesophyll was the main tissue of AGPs distribution in leaf all along. A large number of AGPs were distributed in the vascular bundles of leaf except for a slight decrease in AGPs in the main vein vascular bundles of the leaf during the rapid enlargement period. Leaves not only formed structures adapted to drought, but also formed corresponding AGPs distribution characteristics. |