Figure 7.

Sequence analysis of viral progeny from mixed infections with wild‐type Plum pox virus (PPV) (h‐WT) and a PPV mutant carrying changes that prevent capsid protein (CP) phosphorylation at serine residues 25, 81, 101 and 118 (h‐4SA). Mixtures of extracts of Nicotiana benthamiana plants infected with h‐4SA and h‐WT, combined at the indicated ratios, were used to inoculate N. benthamiana and Nicotiana clevelandii plants. Viruses in infected plants were identified by reverse transcription‐polymerase chain reaction (RT‐PCR) and sequencing of a cDNA fragment covering the CP coding region. An extract from an N. clevelandii plant in which h‐WT and h‐4SA accumulated at similar levels (P2) was used to inoculate new N. benthamiana and N. clevelandii plants, whose viral progeny were assessed as above. Images show the region of sequencing chromatograms corresponding to the triplet encoding CP residue 81 (TCA in h‐WT or GCA in h‐4SA). The viruses identified are indicated beneath the chromatograms; smaller letters indicate lower accumulation. Individual plants (P1–P4 and P2.1–P2.4) were analysed except for the pool of N. benthamiana plants (P1 + P2) indicated by an asterisk (*).