VIEW ARTICLE

Physiology and Biochemistry

Localization and Purification of a Secretory Protein from the Esophageal Glands of Meloidogyne incognita with a Monoclonal Antibody. R. S. Hussey, Professor, Department of Plant Pathology, University of Georgia, Athens 30602; O. R. Paguio(2), and F. Seabury(3). (2)Research associate, Department of Plant Pathology, University of Georgia, Athens 30602; (3)Professor, Department of Biology, The Citadel, Charleston, SC 29483. Phytopathology 80:709-714. Accepted for publication 22 January 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/Phyto-80-709.

Strong labeling of secretory granules in dorsal esophageal glands of preparasitic second-stage juveniles and adult females of Meloidogyne incognita by affinity-purified monoclonal antibody 6D₄ was observed by indirect immunofluorescence microscopy. This antibody also reacted weakly with secretory granules in the subventral esophageal glands of preparasitic juveniles. Postembedding immunogold labeling of ultrathin sections of juvenile esophageal regions revealed that the antigen was segregated around an electron-transparent core in the maxtix of secretory granules in the subventral glands. In the dorsal gland ampulla of adult females, specific gold labeling was localized principally in clumps in the cytoplasm adjacent to secretory granules. The antigen also was detected by immunofluorescence microscopy in stylet secretions of adult females. This secretory component was immunoaffinity purified and appeared to be a large-molecular-weight (M_r > 212,000) glycoprotein as indicated by its slow electrophoretic migration in 7.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and positive staining with periodic acid-Schiff reagent.