Actin Polymerization Is Essential for Pollen Tube GrowthV⃞
AUTOR(ES)
Vidali, Luis
FONTE
The American Society for Cell Biology
RESUMO
Actin microfilaments, which are prominent in pollen tubes, have been implicated in the growth process; however, their mechanism of action is not well understood. In the present work we have used profilin and DNAse I injections, as well as latrunculin B and cytochalasin D treatments, under quantitatively controlled conditions, to perturb actin microfilament structure and assembly in an attempt to answer this question. We found that a ∼50% increase in the total profilin pool was necessary to half-maximally inhibit pollen tube growth, whereas a ∼100% increase was necessary for half-maximal inhibition of cytoplasmic streaming. DNAse I showed a similar inhibitory activity but with a threefold more pronounced effect on growth than streaming. Latrunculin B, at only 1–4 nM in the growth medium, has a similar proportion of inhibition of growth over streaming to that of profilin. The fact that tip growth is more sensitive than streaming to the inhibitory substances and that there is no correlation between streaming and growth rates suggests that tip growth requires actin assembly in a process independent of cytoplasmic streaming.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=58611Documentos Relacionados
- Fine-Tuning of the Cytoplasmic Ca2+ Concentration Is Essential for Pollen Tube Growth1[W]
- Actin-Depolymerizing Factor Mediates Rac/Rop GTPase–Regulated Pollen Tube Growth
- Polymerization of Actin from Maize Pollen.
- Actin Filament Polymerization Regulates Gliding Motility by Apicomplexan ParasitesV⃞
- A plant plasma membrane Ca2+ pump is required for normal pollen tube growth and fertilization