Figure 2.
Replication of PSTVdNT as Well as PSTVdNB in Leaf Mesophyll of Transgenic Tobacco Plants Expressing Their (+)-Strand cDNAs under the Control of the CaMV 35S Promoter.
(A) and (B) In situ hybridization showing the presence of the (−)-strand RNAs of PSTVdNB and PSTVdNT, respectively, in the mesophyll (Me) and phloem (Ph) cells of a young leaf. Bars = 20 μm.
(C) and (D) In situ hybridization showing the presence of the (−)-strand RNAs of PSTVdNB and PSTVdNT, respectively, in the mesophyll (Me) and phloem (Ph) cells of a mature leaf. Bars = 20 μm
(E) RNA gel blots showing the accumulation levels of PSTVdNT (lane 2) and PSTVdNB (lane 3) in 5th leaves of such transgenic plants. There is no viroid accumulation in similar leaves of a nontransgenic plant (lane 1). Bands of 5S rRNA show equal loading of RNA in all lanes. c-(+)PSTVd and l-(+)PSTVd denote circular and linear (+)-PSTVd, respectively.