The C2 protein of Bhendi yellow vein mosaic virus plays an important role in symptom determination and virus replication.

Bhendi yellow vein mosaic virus (BYVMV) that causes bhendi yellow vein mosaic disease is a monopartite begomovirus with an associated betasatellite. Previous studies have shown that C2 protein of BYVMV acts as a suppressor of post transcriptional gene silencing, activates transcription, localizes to nucleus, and interacts with karyopherin α. To probe the role of C2 in symptom determination and virus replication, the infectious clones of BYVMV containing two stop codons in the C2 ORF were created and used for infection studies. The Nicotiana benthamiana plants infiltrated with the infectious clones harboring stop codons in the C2 ORF did not develop any symptoms unlike plants infiltrated with wild-type BYVMV. Southern blotting and real time PCR analysis revealed that the viral load was reduced drastically in the plants infected with BYVMV containing the nontranslatable version of C2 ORF. However, there was a recovery in viral DNA replication, when co-infiltrated with wild-type betasatellite. Hence we conclude that the C2 protein of BYVMV plays an important role in symptom determination and viral DNA replication.