Plants sense carbohydrates and transduce a signal which changes gene expression and the activities of many enzymes. The relationship between changes in gene expression by carbohydrates and the developmental state of the cells is still poorly understood. To gain more knowledge about this relationship, we have analyzed three sugar beet (Beta vulgaris L.) in vitro cell lines residing on distinct differentiation states. Cell suspensions were initiated and cells were incubated for 72h in the medium with sucrose as a control, or treated during the same period with glucose or 3-O-methylglucose (3OMG). Cellular and extracellular proteins, separated electrophoretically, showed that sugar-induced protein expression was cell line-specific. More differences were visible in extracellular and in glycoprotein than on cellular protein patterns. The 3OMG downregulated while glucose upregulated cellular glycoproteins. In the case of extracellular proteins, glucose and 3OMG were equally effective in both downregulation and upregulation of protein expression. Sialic acid was indicated as a glycan conjugate in sugar beet. Carbohydrate-induced gene expression was related to the developmental state of cells.