Table 2.
Characterization of Nine Insertion Mutants of PVA Isolated from the Mutant cDNA Library
| Position of insertion | Propagation in protoplasts | ||||
|---|---|---|---|---|---|
| Region | nt | En masse selection | Inoculation individually | Systemic infection in tobacco plants (ng/g)a | Plasmid name |
| P1 | 235 | nt | + | 5300 (527) | pM14 |
| HC-Pro | 1831 | + | + | 0 | pM65 |
| P3 | 3249 | + | − | nt | pM9 |
| P3 | 3379 | + | + | 5500 (1233) | pM45 |
| CI | 4820 | + | − | nt | pM60 |
| VPg | 5956 | nt | − | nt | pM25 |
| NIa-Pro | 6595 | + | − | nt | pM56 |
| NIb | 8330 | + | − | nt | pM34 |
| CP | 9149 | + | − | nt | pM49 |
| pPVA | no insertion | ni | + | 6150 (375) | pM52 |
nt, not tested because the mutant was probably represented in low numbers in the pPVA-Mu mutant library and was not detected by footprinting analysis prior or after en masse selection in protoplasts; ni, not included in the en masse selection experiment; +, propagation observed in protoplasts; −, no detectable propagation in protoplasts.
a
mean amount of PVA coat protein antigen (in nanogram) per gram (g) of infected leaf (SE) tissue as determined by DAS-ELISA using known amounts of PVA virions as a comparison; nt, not tested.