Identification of a novel C6 protein encoded by tomato leaf curl China virus

Begomoviruses cause significant losses to a wide range of crops worldwide, and a great progress has been made in characterizing some noncanonical proteins encoded by begomoviruses. In the present study, a novel viral protein, C6, was detected in Nicotiana benthamiana plants infected with tomato leaf curl China virus (ToLCCNV). Sequence analyses revealed that the C6 ORF is on the complementary strand of approximately 36% reported begomovirus sequences with conserved amino acid sequence. ToLCCNV C6 specifically localizes to mitochondria. Analysis of deletion mutants showed that C6 possesses an internal mitochondrial targeting signal. Overall, these data uncover a novel begomovirus-encoded protein targeting distinct plant cell organelles.