Figure 3.

Acidification of the pollen tube cytosol triggers the formation of punctate F-actin foci. Representative images of pollen tubes showing F-actin labeled with rhodamine-phalloidin for F-actin visualization after 3 h of treatment with untreated pollen tube (A), SI-induced pollen tube (B), pH 5.5 propionic acid-treated pollen tube (C), or pH 7.0 propionic acid-treated pollen tube (D). Bar = 10 µm. E, Quantification of pollen tubes treated as above. Pollen tubes were scored for F-actin in categories showing untreated (UT) phenotype (filaments; white bars), an SI phenotype (foci; black bars), or an intermediate phenotype (intermediate; gray bars). n = 650 per treatment over 10 independent repeats.