Table 1.
Summary showing the effect of mutations in TMV CP at amino acids Thr28, Thr42, Glu50 and Asp77.
|
CP w.t. |
aVLPs Virion |
bVirus systemic movement in Xanthi-nn Yes |
CP-MR against TMV in transgenic | |
|---|---|---|---|---|
|
cXanthi NN (Local lesions) 99% |
dXanthi nn (Fig. 3) W.t. CP-MR |
|||
| CPE50K | VLPs (long rods) |
eYes | 90-96% | Equal to w.t. CP- MR |
| CPE50R | VLPs(long rods) | Delayed | 99-99.4% | Equal to w.t. CP- MR |
| CPD77N | VLPs (short rods) |
Delayed | 99-100% | Equal to w.t. CP- MR |
| fCPT42W | Highly stable VLP |
No | 96-99% | Better than w.t. CP-MR |
| CPD77R | VLPs (long rods) |
Yes | 96-98% | Better than w.t. CP-MR |
| CPE50M CPD77E |
VLPs (W.t.) VLPs (long rods) |
Yes Yes |
99.8-100% 98.6-99.4% |
Better than w.t. CP-MR Better than w.t. CP-MR |
| CPD77A CPE50Q |
VLPs VLPs (long rods) |
Delayed Delayed |
100% 96-99% |
Better than w.t. CP-MR Better than w.t. CP-MR |
| fCPT28W | No ordered aggergates |
No | 0% | No protection |
| CPD77K | VLPs | No | 0% | No protection |
| CPE50D | VLPs (long rods) | No | 90-97% | No protection |
Effect of each mutation on virion assembly was assessed by introducing the mutation in TMV virus (see also Figure 2).
Ability of TMV mutants to move systemically in Xanthi-nn. Virus systemic movement was measured by comparing the rate symptoms development on systemic leaves: Yes = Development of symptoms on the systemic leaves similar to that in wt TMV inoculated plants (about 8 to 10 days post-inoculation); No = inoculated plants never developed symptoms on the systemic leaves; Delayed = inoculated plants developed symptoms on the systemic leaves a least 25 to 30 days post-inoculation.
CP mutated at one of the above amino acids were expressed in transgenic plants and their ability to provide CP-MR against TMV was measured in transgenic Xanthi-NN and in transgenic.
CP mutated at one of the above amino acids were expressed in transgenic plants and their ability to provide CP-MR against TMV was measured in transgenic Xanthi-nn (Figure 3).
Symptoms produced by TMV-CPE50K on systemic leaves of infected N. tabacum Xanthi-nn plants consisted in leaf curling and local lesions formation.