Fig. 4. Quantification of MP-induced intercellular movement of fluorescent dextrans. Fluorescently labeled dextran (10 kDa) was microinjected either alone or as a mixture with the indicated MP derivatives into N.tabacum (A) or N.benthamiana (B). Fluorescent signal within the injected cell was quantified 5 min (shaded bars) and 30 min (black bars) after injection as described in Materials and methods. The measurements and the indicated standard deviations represent the results of a series of independent microinjections summarized in Table I.