Fig. 3. RT–PCR products of TSWV mRNAs containing (mutant) AMV RNA leaders. (A) TSWV NSs mRNAs containing (mutant) AMV RNA3 leaders. Total RNA was isolated from infected N.tabacum p12 at 7 days post-infection and TSWV NSs mRNAs containing AMV RNA3-derived leaders were RT–PCR amplified using primer NSs1 (RT) and primers NSs2 and A3 (PCR). Products of ∼420 bp represent TSWV NSs mRNAs. 3A17, AMV RNA3 mutant 3A17; 3C18, AMV RNA3 mutant 3C18; 3G18, AMV RNA3 mutant 3G18; 3U18, AMV RNA3 mutant 3U18; WT, wild-type AMV RNA3; TSWV-, uninfected, wild-type AMV RNA3-containing plants; M, 100 bp molecular marker. (B) TSWV N mRNAs containing (mutant) AMV RNA4 leaders. Total RNA was isolated from infected N.tabacum p12 at 7 days post-infection and TSWV N mRNAs containing AMV RNA4-derived leaders were amplified using primer N1 (RT) and primers N2 and A4 (PCR). Products of ∼315 bp represent TSWV N mRNAs. 4A13, AMV RNA4 mutant A13; 4A14, AMV RNA4 mutant A14; 4A15, AMV RNA4 mutant A15; 4A16, AMV RNA4 mutant A16; 4A17, AMV RNA4 mutant A17; 4A18, AMV RNA4 mutant A18; WT, wild-type AMV RNA4; M, 100 bp molecular marker.