C2 and infection: Infection of wild-type plants with BSCTV C2− mutant strain (engineered by introducing a stop codon in the C2 ORF) or infection of SAMDC1 mutant plant with wild-type BSCTV strain resulted in enhanced DNA methylation, reduced viral titer and reduced susceptibility confirming the key role of C2 and SAMDC1 in regulating host DNA methylation.