Figure 6.

Effect of the S97A or S97E mutations on ROP1 function. (A) The S97 residue is conserved only in four Type-I ROPs. (B) Both mutations similarly affect the interaction of ROP1with GEF2 or RIC2 in the yeast two-hybrid system (leu- trp-selection for positive transformation; his- ade- selection for interaction). (C) Effect of the transient expression of wild-type and mutant YFP-fused ROP1 versions driven by the Lat52 pollen-specific promoter on the growth of tobacco pollen tubes. Tip width and tube length were measured for 20–20 fluorescent pollen tubes. Averages and standard deviations are shown. Different letters mean statistically significant difference (p < 0.05; one-way analysis of variance (ANOVA) following Duncan’s multiple range tests). WT—wild type; CA—constitutive active; DN—dominant negative.