Fig. 2

PDS silencing in dcl2drb4 plants inoculated with different CPB1B-based VIGS vectors harboring foreign inserts with varying sizes in the antisense orientation. Images of plants recorded at a 21 and b 38 dpi. At 11 dpi, the upper leaves of CPB1B-inoculated plants gradually exhibit photobleaching. Photobleaching is observed with 2 days delay in CPB1B102- and CPB1B139-infected plants, but this observation is not evident at 18–20 dpi in the CPB1B215-infected plants. The photobleaching of all plants inoculated with CPB1B215 is observed in the main vein, and only a few lateral veins have exhibited photobleaching. The VIGS persists throughout the plant growth period in infected plants and increases with time, as indicated by the photobleaching. c Downregulation of PDS mRNA levels by using different CPB1B-based VIGS vectors with foreign inserts of varied sizes, 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. d Conventional RT-PCR of the genetic stability of the foreign insert in the recombinant virus by using primers TCV-3334F/TCV-4000R. The predicted sizes of RT-PCR amplification products derived from plants infected with CPB-CC, CPB1B, CPB1B102, CPB1B139, and CPB1B215 are 667, 713, 812, 849, and 925 nt, respectively. The RT-PCR products are amplified from all infected samples