CELLULAR LOCALIZATION AND LEVELS OF ARABINOGALACTAN PROTEINS IN LYCIUM BARBARUM'S FRUIT

Lycium barbarum L. contains several polysaccarides which are identified as arabinogalactan proteins (AGPs) and are considered having extensive biological effects and potential health benefits. The crudepolysaccharides were isolated from L. barbarum fruits and then AGPs were purified from the polysaccharides by precipitation. Ten kinds of antibodies (JIM7, JIM8, JIM12, JIM94, JIM13, MAC204, JIM 11, JIM1s9, JIM20, JIM5) were selected from 30 kinds of antibodies by reacting with purified AGPs in Elisa screening.Westem blot analysis confirmed that the anti-arabinogalactan protein antibodies (JIM94, JIM8, JIM13, MAC204) and anti-pectins antibodies (JIM II, JIM20, JIM5) were effective. lmmunolocalization of AGPs showed that these proteins accumulated mainly in the partly parenchyma cells of the exocarp, in the vascular bundles of the mesocarp, and even in the endocarp. Subcellular immunolocalization of AGPs showed that the proteins localized in the plasma and vacuole membranes, vesicles, plastid, mitochondria and other organelles in fruit parenchyma cells. These data suggested that AGPs may take a role as lubricants in fruit parenchyma cell to avoid cell rupture at the rapid growth stage.