Extracellular matrix surface network of embryogenic units of friable maize callus contains arabinogalactan-proteins recognized by monoclonal antibody JIM4 |
| |
Authors: | J ?amaj F Balu?ka M Bobák D Volkmann |
| |
Institution: | Botanisches Institut, Universit?t Bonn, Venusberg 22, D-53115 Bonn, Germany Fax: +49-228-732677; e-mail: unb110@uni-bonn.de, DE Department of Plant Physiology, Comenius University Bratislava, Mlynská dolina B-2, SK-84215 Bratislava, Slovakia, XX
|
| |
Abstract: | Embryogenic units of friable maize callus are formed as globular or oblong packets of tightly associated meristematic cells.
These units are surrounded by conspicuous cell walls visible in light microscopy after staining with basic fuchsin. Transmission
electron microscopy revealed that embryogenic cells are rich in endoplasmic reticulum, polysomes and small protein bodies,
and that the outermost layer of their cell walls is composed of fibrillar material. Electron microscopy has also shown that
this material covers the surface of embryogenic cells as a distinct layer which we denote as extracellular matrix surface
network (ECMSN). Employing histochemical staining with β-glucosyl Yariv phenylglycoside, we localized arabinogalactan-proteins (AGPs) to the outer cell walls of embryogenic units
including ECMSN. The most prominent staining was found in cell-cell junction domains. Large non-embryogenic callus cells were
not stained with this AGP-specific dye. Immunofluorescence and silver-enhanced immunogold labelling using monoclonal antibody
JIM4 has shown that the ECMSN of embryogenic cells is equipped with JIM4 epitope, while non-embryogenic callus cells are devoid
of this epitope. We propose that some specific AGPs of the ECMSN might be relevant for cell-cell adhesion and recognition
of embryogenic cells during early embryogenic stages, and that the JIM4 antibody can serve as an early marker of embryogenic
competence in maize callus culture.
Received: 13 March 1998 / Revision received: 6 June 1998 / Accepted: 1 July 1998 |
| |
Keywords: | Arabinogalactan-proteins Somatic embryogenesis Zea mays |
本文献已被 SpringerLink 等数据库收录! |
|