Click on any
image for a more
detailed view

Pathogen Biology

Hosts for TMV include tobacco (Figure 1), tomato (Figure 5), and other solanaceous plants. Currently, yield losses for tobacco due to TMV are estimated at only 1% because resistant varieties are routinely grown. In contrast, losses of up to 20% have been reported for tomato. In addition, poor fruit quality may reduce the value of the crop on the commercial fresh market.

Figure 1

Figure 5

TMV is the type member of a large group of viruses within the genus Tobamovirus. The rod-shaped virus particles (virions) of TMV measure about 300 nm x 15 nm (Figure 6). A single TMV particle is composed of 2,130 copies of the coat protein (CP) that envelope the RNA molecule of about 6,400 nucleotides (Figure 7). This single-stranded RNA encodes four genes: two replicase-associated proteins that are directly translated from the TMV RNA, and the movement protein and a coat protein that are translated from subgenomic RNAs (Figures 8 and 9).

Figure 7	Figure 6
Figure 8
Figure 9

RETURN TO TOP