Fig. 5

Complementation of the h mutant phenotype. a TRV carrying the wild-type H ORF and an AmPDS fragment failed to complement the h mutant phenotype (genotype h/h) and leaves remained hairy. b The same virus triggered VIGS of H and AmPDS in the wild-type plants (genotype H/H). c TRV with a synonymous H-encoding sequence (SynH) and AmPDS fragment also failed to complement h. d Unlike TRV with the wild-type H ORF, the SynH TRV did not cause VIGS of the wild-type H gene, though it triggered VIGS of AmPDS. The plants in c and d were grown together at a different time to those in (a and c). Differences in growth conditions, rather than the TRV, might therefore account for differences in purple anthocyanin expression. e Alignment of SynH with wild-type H and the most H-like gene (GRX6c) expressed in the h/h NIL. Identical nucleotides are boxed black. f–h TRV carrying the SynH sequence without AmPDS, led to leaf blades with large areas lacking trichomes in the h mutant NIL (remaining trichomes in the leaf blade are indicated by white arrowheads). Any trichomes that remained within the otherwise bald areas formed over major secondary veins (V). i, j Bald areas were not seen in the h mutant NIL infected with empty TRV. Scale bars in (f–j) show 1 mm. k TRV2 RNA was detected, using primers for its CP gene, in all bald (B) areas in h mutants and in corresponding hairy (H) areas from the same leaf or plant. Amplificiation of the Ubiquitin1 (AmUBI) gene was used as a control for cDNA and pTRV2 and mock-inoculated plants as positive and negative controls for TRV detection, respectively