Figure 8.

Detection of PLMVd (+) and (−) Strands in GF-305 Peach Leaves Infected by Two Viroid Variants.

(A) In situ hybridization of transverse sections from the albino sector of a leaf infected by variant PC-C40 (top) and from a healthy leaf (bottom). The sections were hybridized with riboprobes for detecting (+) (left) and (−) (right) PLMVd strands. Hybridization signals appear with a blue-violet color.

(B) RNA gel blot hybridizations of different RNA preparations with riboprobes for detecting (+) (left) and (−) (right) PLMVd strands following fractionation by denaturing PAGE on a 5% gel. The positions of the monomeric circular (mc) and linear (ml) PLMVd RNAs are indicated at left. The bottom panels show the ethidium bromide pattern of the top section of the gels (for additional details, see the legend to Figure 5E). Results are representative of three independent experiments with similar outcome: the progeny of variant PC-C40 accumulated at a significantly higher level (50.5% ± 4.5%) in the albino sectors than in the green sectors of the same leaf. Loadings were equalized with respect to the nucleus-encoded rRNAs, which remain unaffected in symptomatic and asymptomatic tissues.