Wheat germ agglutinin accumulation in coleoptiles of different genotypes of wheat. Localization by monoclonal antibodies

We have produced a library of 18 monoclonal antibodies (mABs) against wheat germ agglutinin (WGA). It was difficult to establish antibody-producing hybridomas when soluble WGA was used for immunization. The frequency of specific hybridomas was increased, however, by injecting mice with insoluble antigen-antibody complex.We distinguished groups of mABs that are especially efficient for particular immunoassays. One group (mABs 005, 006, 007, 009, 011, 014, 015, 016, 017, 018, 019) strongly immunostains denatured antigen on electroblots of sodium dodecyl sulfate polyacrylamide gels. A second group (all mABs except 012) shows high activity for WGA when native protein is analyzed by enzyme-linked immunosorbent assay. The third group (mABs 002, 005, 008, 009, 010, 011, 014, 016, 018, 019) works well for immunocytochemistry.We used the mABs to localize WGA in wheat varieties of various ploidy and with different ancestral wheat genomes. Whereas lectin is detected in the coleoptile of varieties with hexaploid and DD and SS genomes, WGA is absent in the coleoptile of the diploid Triticum monococcum (AA). Lectin accumulates in the coleoptile of mature embryos of T. monococcum, however, when they are treated with abscisic acid.Abbreviations ABA abscisic acid - ELISA enzyme-linked immunosorbent assay - Ig immunoglobulin - mAB monoclonal antibody - PAGE polyacrylamide gel electrophoresis - PBS 12 mM KH₂PO₄, 10 mM Na₂HPO₄, 25 mM KCl, and 140 mM NaCl, pH 7.2 - SDS sodium dodecyl sulfate - WGA wheat germ agglutinin