The structure elucidation of protein-linked N-glycans in plants has raised interest in the past years due to remarkable physiological roles attributed to these modifications: control of protein folding, biological activity and stability of proteins. However, little information about the glycoprotein patterns related to plant cell differentiation, dedifferentiation and transformation is available. A spontaneous switch from an organised to unorganised way of growth in the Mammillaria gracillis Pfeiff. (Cactaceae) tissue culture makes this system suitable to study plant morphogenesis. In this work the use of 2D-PAGE-MALDI methodology for the characterisation of carbohydrates released from plant glycoproteins is described. Proteins from different Mammillaria tissues (shoot, callus, hyperhydric regenerant and TW tumour) were separated by 2-D SDS-polyacrylamide gel electrophoresis, transferred to a nitrocellulose membrane and incubated with Con A to detect N-glycosylated proteins. In order to discover if the same protein can have various N-glycan structures depending on the organisation status of the tissue, the selected glycoprotein spot, which was common for all investigated tissues, was excised from the gels and digested by PNGase A. The released oligosaccharides were analysed by MALDI-TOF MS. Results obtained in this study indicate that the N-glycosylation pattern of the protein is clearly dependent on level of plant tissue organisation and can be related to the specific morphogenic status.