VIEW ARTICLE

The Tracing of Ingested TMV ¹²⁵I in the Aphid Myzus persica. Willem G. Langenberg, Research Plant Pathologist, Crops Research Division, ARS, USDA, Department of Plant Pathology, University of Nebraska, Lincoln 68503; Helen F. Schroeder, Laboratory Technician, Department of Plant Pathology, University of Nebraska, Lincoln 68503. Phytopathology 61:15-21. Accepted for publication 15 July 1970. DOI: 10.1094/Phyto-61-15.

The advisability of using a fixative known to fix a virus in situ in plants for studying plant virus localization in insects was demonstrated. Green peach aphids (Myzus persicae) were fed ¹²⁵I-labeled and nonlabeled tobacco mosaic virus (TMV), ¹²⁵I-labeled rabbit gamma globulin, and Na ¹²⁵I through parafilm membranes. Virus was detected in the first ventriculus after fixation at pH 3.8 with osmic acid, a fixative which preserves TMV inclusion bodies in plant cells. No virus was detected in the first ventriculus after fixation with neutral phosphate buffered glutaraldehyde followed by osmic acid, a fixative which does not preserve TMV inclusions in plant cells. After the pH 3.8 osmic acid fixation, large amounts of TMV were found in the first ventriculus, lesser amounts in the rest of the digestive tract, and none in the rest of the aphid. ¹²⁵I was incorporated only in the trachea and cuticle in aphids fed Na ¹²⁵I. No label was found in the trachea and cuticle in aphids fed ¹²⁵I-labeled virus or gamma globulin. No ¹²⁵I was released from the labeled proteins.