Fig. 1

CPB-CC-based vectors harboring 46 nt PDS fragment inserted in both orientations can effectively trigger PDS silencing in Arabidopsis. a PDS silencing induced by CPB-CC-based vectors in dcl4 plants. Images are recorded at 25 dpi. At 11 dpi, the upper uninoculated leaves of CPB1F- or CPB1B-infected plants exhibit a photobleaching phenotype in the upper leaves, resulting from the reduction in the expression level of PDS. CPB1F and CPB1B represent a 46 nt PDS fragment inserted in the sense and the antisense orientations, respectively. b Diagrams of TCV, CPB-CC, and CPB1B constructs. The CPB-CC construct is produced by changing the AT dinucleotides to CC at nt 3807 to 3808, within the 3′ UTR of CPB, which has R130T mutation denoted by a red star, resulting in a new KpnI site. The CPB1B construct is produced by fusing 46 nt PDS fragment in CPB-CC in the antisense orientation. c Downregulation of PDS mRNA levels by CPB1F and CPB1B in dcl4 plants as determined using semiquantitative RT-PCR. The samples are collected at 14 dpi. The AtActin1 mRNA is used as a control to ensure that similar amounts of RNA are used in all reactions