DNA replication of wheat dwarf virus, a geminivirus, requires two cis-acting signals.

Replication of the single-stranded DNA genome of wheat dwarf virus (WDV) leads to the accumulation of covalently closed double-stranded DNA of genome length in infected cells. By studying the replication properties of a naturally occurring deletion mutant of WDV isolated from infected plants and of deletion mutants constructed in vitro, we have defined cis-acting regions required for viral DNA replication. The results show that two distinct regions are required in cis to yield the normal replicative forms of WDV-DNA.