Interestingly, although the NbSKη interaction-compromised TLCYnV C4 mutant [C4(T35A)] failed to induce infection-like symptoms, we found that PVX-TLCYnV C4(T35A) could suppress TGS in 16c-TGS transgenic N. benthamiana plants (Fig 6A), while the TLCYnV C4 mutant deficient in NbDRM2-binding could not (Fig 6A); this visual evaluation was confirmed by western blot to detect GFP (Fig 6B). This evidence concerns the gene C4A and infection.