Figure 8.

G76A and G156A mutants replicate and spread in rub-inoculated leaves. (A) Infection was monitored by whole mount in situ hybridization in leaves rub-inoculated with wild type PSTVd (WT), G76A, or G156A at 8, 10 and 12 dpi. Mock inoculation was a negative control. Purple dots (some indicated by red arrows) are viroid hybridization signals in nuclei. Bars = 100 μm. Images for PSTVd WT, G76A, and G156A are representative of >200 visual fields. (B). Mean numbers of infected cells per visual field. Asterisks indicate significant differences (P < 0.05) as determined by Student's t test. Bars indicate standard error of the mean.