Major actin filament stabilizing factor and regulator of actin dynamics. Binds actin and actin filament bundles in a Ca(2+)-insensitive manner, but caps the barbed end of actin filaments and is able to sever them in a calcium-dependent manner. Required for the construction of actin collars in pollen tubes. Acts synergistically with VLN2 (AC O81644) to regulate polarized pollen tube growth. Present in the apical and subapical regions of pollen tubes. Ubiquitous, but expressed preferentially in pollen and stamens. Retarded pollen tube growth, but no effect on pollen germination, root hair growth, organization or amount of filamentous actin in pollen grains or tubes. Increased sensitivity to latrunculin B (LatB) and instability of actin filaments in pollen tubes. Decreased severing frequency of actin filaments. Vln2 and vln5 double mutants have pollen tubes curled and wider at some regions along the tube. They accumulate actin filaments at the tips of pollen tubes (PubMed:23715472). Belongs to the villin/gelsolin family.