A set of cell surface glycoproteins forms an early position, but not cell type, in the root apical carota L

Abstract

A monoclonal antibody (JIM4) has been derived that series of glycoproteins associated with the plasma suspension-cultured carrot cell line and also an proteoglycan secreted by the cultured cells. indicated that the plasma membrane antigen(s) specific to certain cells of Daucus carota L. apex JIM4 labelled two segments of the stele. These the poles of the protoxylem. An axis of unlabelled two phloem regions. Two sections of the pericycle with oblique longitudinal divisions were particularly This pattern of reactive cells, reflecting cell specific future cell type, would appear to be a unique plants. The association of JIM4 antigens with these maintained through the transition from root to the cotyledons and the mature plant. Examination of JIM4 ultrathin frozen sections of the carrot seedling root indicated that the expression of the antigen is a very root development. Cells express the surface epitope, cells of the dome of apical initials, before the vascular tissue can be discerned and well before its differentiation.