Low concentration of LatB dramatically changes the microtubule organization and the timing of vegetative nucleus/generative cell entrance in tobacco pollen tubes.

Low concentration of LatB inhibits not only the actin polymerization, but also induces profound alteration of MT distribution in pollen tubes of Nicotiana tabacum. The short randomly oriented MTs in the apical and subapical regions, became organized as bundles forming subapical rings or basket-like structures, surrounding the apex. Moreover, the depolymerization of AFs in the cortical regions of the apex and subapical region affects the timing of entrance of the vegetative nucleus and generative cell into the pollen tube.