We studied the separation of distinct compartments of the Golgi complex in rice and tobacco employing the discontinuous sucrose density gradient centrifugation technique with EDTA or MgCl2. In the presence of EDTA, rice Golgi marker enzymes, nucleoside diphosphatase and N-acetylglucosaminyltransferase were fractionated in the 28 and 33% sucrose fractions, respectively. Peanut lectin-recognized glycoproteins and reversibly glycosylated polypeptide-1 that are shown to be located at Golgi complex were broadly distributed around a 31.5% sucrose density. Under a MgCl2-supplemented condition, the peak of nucleoside diphosphatase was shifted to 29 and 37% sucrose and N-acetylglucosaminyltransferase was distributed in the 37% sucrose fraction. The distribution of peanut lectin-recognized glycoproteins and reversibly glycosylated polypeptide-1 were also shifted to the 34.5% sucrose fraction. Furthermore, glucan synthase-I and UDP-glucose pyrophosphorylase were fractionated in the 26.5% sucrose fraction, regardless of the presence or absence of MgCl2. These results indicate that there exist at least four distinct compartments of the rice Golgi complex. The tobacco Golgi marker enzymes and Golgi-localized proteins were distributed in the 30-31% sucrose fractions in the presence of EDTA and slightly shifted to the 32-33% sucrose fractions under a MgCl2-supplemented condition. These results suggest that the sedimentation behavior of compartments of the rice Golgi complex in the gradients is specific for rice cells. © 2001 Elsevier Science Ireland Ltd. All rights reserved.