Virus-induced gene silencing (VIGS) in N. benthamiana was done as described [65, 66] . To generate the VIGS vector (pTRV2-eEF1BcNt), a 314-bp cDNA fragment of NteEF1Bc was RT-PCR amplified from a total RNA extract of N. benthamiana using the following pair of primers: #2993 (CGCGGATCCAAAG-GTTTCTGGGACATGTATGA) and #2994 (CGCCTCGA-GACACGCTCCTTCTGTGATTCATC) and inserted into the corresponding (BamHI/XhoI) restriction sites of pTRV2 plasmid.