Fig 4. Predicted targeting of the StTCP23 mRNA by vd-sRNA.

(A) Potato leaves were agroinfiltrated with transient vector expressing (a) GFP: StTCP23, (b) GFP: StTCP23 plus empty vector, (c) GFP: StTCP23 plus TR-amiR46, (d) wild type control. At 5 dpi the leaves were photographed (4X) using a fluorescence microscope. (B) Potato leaves were agroinfiltrated using the same plasmid combinations as in (A). At 5 dpi relative GFP expression was quantified by RT-qPCR. (C) Nested PCR products obtained from 3′ RACE Exp.1 and 3′RACE Exp.2, using primers targeting the StTCP23 mRNA were separated by 2.0% agarose gel electrophoresis. Predicted structure of the StTCP23 mRNA/vd-sRNA duplex formed by siRNAs derived from the PSTVd-RG1. Arrows indicate the 3′ termini of StTCP23 mRNA fragments isolated from the PSTVd-infected plants, as identified by 3′RACE Exp.1 and by 3′ RACE Exp.2, with the frequency of each termini shown.