Fig. 2. Morphology and viability of PMEI-1, PMEI-2, pme3 and WT protoplasts. (A) Microphotographs of WT, PMEI-1, PMEI-2 and pme3 protoplasts, scale bars 10 µm. (B) Protoplast diameter. (C) Protoplasts were stained with 0.01% Fluorescein Diacetate (FDA) and the viable cells indicated by green fluorescence were visualized using a fluorescence microscope. The bright field images of protoplasts are also shown. (D) Protoplast viability expressed as percentage of live protoplasts released with respect to the total number of protoplasts released after 3 h of enzymatic treatment. Bars represent means ± SD of three independent experiments (n À 100 in each experiment). The same letters indicate no statistically significant differences, according to ANOVA followed by Tukey's test (P> 0.05). Scale bar = 100 µm.