Abstract
The direct method of staining plant viruses with fluorescein isothiocyanate-labeled antibody was employed in an attempt to detect tobacco mosaic virus (TMV) in infected tobacco leaf tissues. For obtaining a specific staining, conjugated TMV antiserum was separated from its mixing free dye by being absorbed twice in healthy tobacco tissue acetone powder and by passing it through a DEAE-cellulose column. The virus, that was stained specifically by this method, was recognized as exhibiting a yellow-green fluorescence.
TMV was distributed in epidermal, palisade and spongy tissues, and phloem of the infected leaves of tobacco plants (Nicotiana tabacum var. Bright Yellow). However, xylem did not contain any detectable amount of the virus. Epidermal strips showed a staining pattern consisting with the scattered fluorescence, which seemed to indicate that the reaction was only positive in the parenchymatous tissue adhering to epidermal tissues. This suggests that the conjugated TMV antiserum does not penetrate the intact cell wall.
In the leaves of N. glutinosa, which shows necrotic local lesions, TMV was concentrated in the site of necrosis, but not detected in the surrounding healthy tissues. Another effort to detect the presence of TMV was successfully made using tobacco seed whose surface was contaminated with TMV.
