The current work also provides evidence that eEF1Bc is a key factor in TBSV replication in yeast ( Figure 1 ) and in N. benthamiana (Figure 7) . Since eEF1Bc is a highly conserved protein in all eukaryotes [32] , it is not surprising that yeast eEF1Bc, similar to the plant eEF1Bc, can be co-opted for TBSV replication. Interestingly, deletion of either TEF3 or TEF4 genes reduced TBSV repRNA accumulation in yeast, suggesting that eEF1Bc is present in limiting amount or eEF1Bc is present in not easily accessible forms (in protein complexes) and/or locations in yeast cells. Silencing of eEF1Bc in N. bethamiana showed even more inhibition of TBSV RNA accumulation than deletion of eEF1Bc genes in yeast. This is likely due to the robust antiviral response (i.e., induced gene silencing) of the plant host, which could result in degradation of the small amount of viral RNA produced by the less efficient viral RNA replication in the presence of limited eEF1Bc in the knock-down plants.