TABLE 2.
Symptoms and rates of aphid transmission in tobacco plants infected with CMV βH-βI loop mutantsa
| Strain | Symptom(s) on tobaccob
|
Aphid transmissionc [no. of plants infected/total (%)] | |
|---|---|---|---|
| Inoculated leaves | Systemically infected leaves | ||
| D191A mutant | Chlorotic LL | Mottle-mosaic | 28/64 (44) |
| D191K mutant | Chlorotic LL | Mottle-mosaic | 0/20 (0) |
| D192A mutant | Chlorotic LL | Mottle-mosaic | 0/30 (0) |
| D192K mutant | Necrosis | Mottle-mosaic, necrosis | 8/27 (30) |
| L194A mutant | Chlorotic LL | Yellow mosaic, necrotic flecks | 3/31 (10) |
| E195A mutant | Chlorotic LL | Mottle-mosaic | 4/47 (9) |
| E195K mutant | Chlorotic LL | Mottle-mosaic | 1/35 (3) |
| D197A mutant | Chlorotic LL | Mottle-mosaic | 5/58 (9) |
| D197K∗d mutant | Chlorotic LL | Mottle-mosaic | 20/20 (100) |
| Fny (wild type) | Chlorotic LL | Mottle-mosaic | 85/87 (98) |
a
Tobacco leaves were mechanically inoculated with in vitro-transcribed RNAs or crude sap extracts from infected plants.
b
Symptoms were evaluated 7 to 21 days postinoculation. LL, local lesions.
c
Transmission was tested with 10 Aphis gossypii aphids per tobacco plant.
d
The D197K mutant appeared to be inviable, as no systemic infection was observed. The asterisk in D197K∗ indicates the presence of a second-site mutation, A193E, as described in the text; this was the only recovered progeny.