Slowly migrating DNAs are converted into ocDNA by Taq (A) or T4 (B) DNA polymerase treatment. The blots were hybridized with a C1-sense RNA probe. The positions of ocDNA, linear DNA (linDNA), scDNA, and cssDNA forms of viral DNA are indicated. Slowly migrating viral DNAs are indicated with an asterisk (∗). (A) TNAs were extracted from wt protoplasts at 72 h posttransfection with pTOM6 alone (the two lanes on the right) or together with pTOM100C4(−) or pTOM100NT and analyzed directly (−) or following incubation with Taq DNA polymerase for the time indicated below. (B) TNAs were extracted from wt or transgenic (102.22) protoplasts at 72 h posttransfection with pSP97 (TYLCSV-ES[1]) and analyzed following a 1-h incubation with (+) or without (−) <t>T4</t> DNA polymerase. Lane C, TNAs from a TYLCSV-infected tomato plant digested with Bgl II to show migration of linear DNA.