Profilin promotes formin-mediated actin filament assembly and vesicle transport during polarity formation in pollen
Open Access
- 8 February 2021
- journal article
- research article
- Published by Oxford University Press (OUP) in THE PLANT CELL ONLINE
- Vol. 33 (4), 1252-1267
- https://doi.org/10.1093/plcell/koab027
Abstract
Pollen germination is critical for the reproduction of flowering plants. Formin-dependent actin polymerization plays vital roles in vesicle trafficking and polarity establishment during this process. However, how formin-mediated actin assembly is regulated in vivo remains poorly understood. Here, we investigated the function of reproductive profilin 4 and 5 (PRF4 and PRF5) in polarity establishment during pollen germination in Arabidopsis thaliana. Our data showed that the actin filament content was reduced in the prf4 prf5 double mutant and substantially increased in both PRF4- and PRF5-overexpressing pollen grains. By contrast, the positive effect of profilin in promoting actin polymerization was abolished in a formin mutant, atfh5. In addition, the interaction between Arabidopsis formin homology 5 (AtFH5) and actin filaments was attenuated and the trafficking of AtFH5-labeled vesicles was slowed in prf4 prf5 pollen grains. Formation of the collar-like structure at the germination pore was also defective in prf4 prf5 pollen grains as the fast assembly of actin filaments was impaired. Together, our results suggest that PRF4 and PRF5 regulate vesicle trafficking and polarity establishment during pollen germination by promoting AtFH5-mediated actin polymerization and enhancing the interaction between AtFH5 and actin filaments.Keywords
Funding Information
- National Natural Science Foundation of China (91854206, 31770206, 31870174, 32070194)
- China Postdoctoral Science Foundation (2020M670197)
This publication has 46 references indexed in Scilit:
- Modulation of formin processivity by profilin and mechanical tensioneLife, 2018
- Profilin-Dependent Nucleation and Assembly of Actin Filaments Controls Cell Elongation in ArabidopsisPlant Physiology, 2015
- Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growthThe Plant Journal, 2015
- Overexpression of profilin 3 affects cell elongation and F-actin organization in Arabidopsis thalianaPlant Cell Reports, 2012
- A transmembrane formin nucleates subapical actin assembly and controls tip-focused growth in pollen tubesProceedings of the National Academy of Sciences of the United States of America, 2010
- Regulation of Actin Dynamics in Pollen Tubes: Control of Actin Polymer LevelJournal of Integrative Plant Biology, 2009
- TECHNICAL ADVANCE: Temperature as a determinant factor for increased and reproducible in vitro pollen germination in Arabidopsis thalianaThe Plant Journal, 2007
- Silencing profilin-1 inhibits endothelial cell proliferation, migration and cord morphogenesisJournal of Cell Science, 2006
- Latrunculin B Has Different Effects on Pollen Germination and Tube GrowthTHE PLANT CELL ONLINE, 1999
- chickadee encodes a profilin required for intercellular cytoplasm transport during Drosophila oogenesisCell, 1992