Figure 9.

Green fluorescent protein fusion constructs (GFP:MP) of the mutants are impaired in cell‐to‐cell movement. Fully developed Nicotiana benthamiana leaves were agroinfiltrated with pGC‐RNA1, pGC‐RNA3 and the selected pGC‐GFP:MP construct in 1 : 10 serial dilutions of Agrobacterium suspensions grown to an optical density of 0.4 at 600 nm. Single‐cell transfection was obtained with the 10⁻³ dilution. Fluorescence of the GFP:MPwt fusion (GFP fusion with wild‐type movement protein) was observed in the initially infected cell and in one or more of the surrounding cells, whereas it remained limited to the transfected cell for mutants GFP:MP98, GFP:MP150 and GFP:MP169, as observed for the pBin:GFP negative control. With further dilutions of all construct mixtures, including that with GFP:MPwt, no fluorescence was visible. For each genotype, about 20 cells were imaged. Scale bars, 20 µm.