Isolation and characterization of a jacalin-related mannose-binding lectin from salt-stressed rice ( Oryza sativa ) plants

• DOI: 10.1007/s004250050705
• Publication Date: 2002-08-25T09:25:39Z
• Authors: Willy J. Peumans; Annick Barre; Corinne Houles As...; Paula Rovira; Pierre Roug�; Paul Proost; Paolo Truffa-Bachi; Ali A. H. Jalali; Els J. M. Van Damme; Wenling Zhang
• Keywords: Models, Molecular; 0301 basic medicine; Mice, Inbred BALB C; Molecular Sequence Data; Oryza; Hemagglutination Tests; Chromatography, Ion Exchange; Mass Spectrometry; Protein Structure, Tertiary; Mice, Inbred C57BL; Mice; 03 medical and health sciences; Mannose-Binding Lectins; Lectins; Animals; Humans; Electrophoresis, Polyacrylamide Gel; Amino Acid Sequence; Rabbits; Plant Lectins; Mannose; Plant Proteins

A novel plant lectin was isolated from salt-stressed rice (Oryza sativa L.) plants and partially characterized. The lectin occurs as a natural mixture of two closely related isoforms consisting of two identical non-covalently linked subunits of 15 kDa. Both isoforms are best inhibited by mannose and exhibit potent mitogenic activity towards T-lymphocytes. Biochemical analyses and sequence comparisons further revealed that the rice lectins belong to the subgroup of mannose-binding jacalin-related lectins. In addition, it could be demonstrated that the lectins described here correspond to the protein products of previously described salt-stress-induced genes. Our results not only identify the rice lectin as a stress protein but also highlight the possible importance of protein-carbohydrate interactions in stress responses in plants.