Abstract
The actin cytoskeleton plays a crucial role in pollen tube growth. In elongating pollen tubes the organization and arrangement of actin filaments (AFs) differs between the shank and apical region. However, the orientation of AFs in pollen tubes has not yet been successfully demonstrated. In the present work we have used myosin II subfragment 1 (S1) decoration to determine the polarity of AFs in pollen tubes. Electron microscopy studies revealed that in the shank of the tube bundles of AFs exhibit uniform polarity with those close to the cell cortex having their barbed ends oriented towards the tip of the pollen tube while those in the cell center have their barbed ends oriented toward the base of the tube. At the subapex, some AFs are organized in closely packed and longitudinally oriented bundles and some form curved bundles adjacent to the cell membrane. In contrast, few AFs are dispersed with random orientation in the extreme apex of the pollen tube. Our results confirm that the direction of cytoplasmic streaming within pollen tubes is determined by the polarity of AFs in the bundles.


Abbreviations
- GFP:
-
Green fluorescent protein
- EGTA:
-
Ethylene glycol tetraacetic acid
- Mes:
-
Sigma BioUltra buffer
References
Cai G, Moscatelli A, Cresti M (1997) Cytoskeletal organization and pollen tube growth. Trends Plant Sci 2:86–91
Cárdenas L, Lovy-Wheeler A, Wilsen KL, Hepler PK (2005) Actin polymerization promotes the reversal of streaming in the apex of pollen tubes. Cell Motil Cytoskeleton 61:112–127
Cárdenas L, Lovy-Wheeler A, Kunkel JG, Hepler PK (2008) Pollen tube growth oscillations and intracellular calcium levels are reversibly modulated by actin polymerization. Plant Physiol 146:1611–1621
Chen CY, Wong EI, Vidali L, Estavillo A, Hepler PK, Wu H, Cheung AY (2002) The regulation of actin organization by actin-depolymerizing factor in elongating pollen tubes. Plant Cell 14:2175–2190
Chen T, Teng N, Wu X, Wang Y, Tang W, Amaj J, Baluka F, Lin J (2007) Disruption of actin filaments by latrunculin B affects cell wall construction in Picea meyeri pollen tube by disturbing vesicle trafficking. Plant Cell Physiol 48:19–30
Cheung AY, Wu HM (2004) Overexpression of an Arabidopsis formin stimulates supernumerary actin cable formation from pollen tube cell membrane. Plant Cell 16:257–269
Derksen J, Ruttens T, van Amstel T, de Win A, Doris F, Steer M (1995) Regulation of pollen tube growth. Acta Bot Neerl 44:93–119
Feijó JA, Costa SS, Prado AM, Becker JD, Certal AC (2004) Signalling by tips. Curr Opin Plant Biol 7:589–598
Fu Y, Wu G, Yang Z (2001) GTPase dependent dynamics of tip localized F-actin controls tip growth in pollen tubes. J Cell Biol 152:1019–1032
Geitmann A, Snowman BN, Emons AMC, Franklin-Tong VE (2000) Alternations in the actin cytoskeleton of pollen tubes are induced by the self-incompatibility reaction in Papaver rhoeas. Plant Cell 12:1239–1252
Gibbon BC, Kovar DR, Staiger CJ (1999) Latrunculin B has different effects on pollen germination and tube growth. Plant Cell 11:2349–2363
Hepler PK, Vidali L, Cheung AY (2001) Polarized cell growth in higher plants. Annu Rev Cell Dev Bio 117:159–187
Hwang JU, Gu Y, Lee YJ, Yang Z (2005) Oscillatory ROP GTPase activation leads the oscillatory polarized growth of pollen tubes. Mol Biol Cell 16:5385–5399
Justus CD, Anderhag P, Goins JL, Lazzaro MD (2004) Microtubules and microfilaments coordinate to direct a fountain streaming pattern in elongating conifer pollen tube tips. Planta 219:103–109
Kohno T, Shimmen T (1988) Accelerated sliding of pollen tube organelles along Characeae actin bundles regulated by Ca2+. J Cell Biol 106:1539–1543
Kohno T, Chaen S, Shimmen T (1990) Characterization of the translocator associated with pollen tube organelles. Protoplasma 154:179–183
Lancelle SA, Hepler PK (1992) Ultrasructure of freeze-substituted pollen tubes of Lilium longiflorum. Protoplasma 167:215–230
Lancelle SA, Cresti M, Hepler PK (1987) Ultrasructure of the cytoskeleton in freeze-substituted pollen tubes of Nicotiana alata. Protoplasma 140:141–150
Li Y, Zee SY, Liu YM, Huang BQ, Yen LF (2001) Circular F-actin bundles and a G-actin gradient in pollen and pollen tubes of Lilium davidii. Planta 213:722–730
Lovy-Wheeler A, Wilsen KL, Baskin TI, Hepler PK (2005) Enhanced fixation reveals the apical cortical fringe of actin filaments as a consistent feature of the pollen tube. Planta 221:95–104
Margossian SS, Lowely S (1982) Preparation of myosin and its subfragments from rabbit skeletal muscle. Methods Enzymol 85:55–71
Noguchi T, Lenartowska M, Miller KG (2006) Myosin VI stabilizes an actin network during Drosophila spermatid individualization. Mol Biol Cell 17:2559–2571
Noguchi T, Lenartowska M, Rogat AD, Frank DJ, Miller KG (2008) Proper cellular reorganization during Drosophila spermatid individualization depends on actin structures composed of two domains, bundles and meshwork, that are differentially regulated and have different functions. Mol Biol Cell 19:2363–2372
Ren H, Xiang Y (2007) The function of actin-binding proteins in pollen tube growth. Protoplasma 230:171–182
Tang X, Lancelle SA, Hepler PK (1989) Fluorescence microscopic localization of actin in pollen tubes: comparsion of actin antibody and phalloidin staining. Cell Motil Cytoskeleton 12:216–224
Tominaga M, Yokota E, Vidali L, Sonobe S, Hepler PK, Shimmen T (2000) The role of plant villin in the organization of the actin cytoskeleton, cytoplasmic streaming and the architecture of the transvacuolar strand in root hair cells of Hydrocharis. Planta 210:836–843
Tylor LP, Hepler PK (1997) Pollen germination and tube growth. Annu Rev Plant Physiol Plant Mol Biol 48:461–491
Vidali L, Hepler PK (2001) Actin and pollen tube growth. Protoplasma 215:64–76
Vidali L, Yokota E, Cheung AY, Shimmen T, Hepler PK (1999) The 135 kDa actin-bundling protein from Lilium longiforum pollen is the plant homologue of villin. Protoplasma 209:283–291
Vidali L, McKenna ST, Hepler PK (2001) Actin polymerization is essential for pollen tube growth. Mol Biol Cell 12:2534–2545
Yokota E, Shimmen T (1999) The 135-kDa actin-bundling protein from lily pollen tubes arranges F-actin into bundles with uniform polarity. Planta 209:264–266
Yokota E, Takahara K, Shimmen T (1998) Actin-bundling protein isolated from pollen tubes of lily. Biochemical and immunocytochemical characterization. Plant Physiol 116:1421–1429
Yokota E, Vidali L, Tominaga M, Tahara H, Orii H, Morizane Y, Hepler PK, Shimmen T (2003) Plant 115-kDa actin-filament bundling protein, P-115-ABP, is a homologue of plant villin and is widely distributed in cells. Plant Cell Physiol 44:1088–1099
Acknowledgments
We thank Tatsuhiko Noguchi (Laboratory of Morphogenetic Signaling, Center for Developmental Biology, RIKEN Kobe, Japan) for inspiration to modify the actin S1 decoration technique in plant cells, and Deborah J. Frank (Biology Department, Washington University in St. Louis, US) for critical reading of the manuscript. We also thank Olga Narbutt and Michal Swidzinski for their excellent technical assistance. This project was supported by the Ministry of Science and Higher Education in Poland, grant No. N303 023 32/1034.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lenartowska, M., Michalska, A. Actin filament organization and polarity in pollen tubes revealed by myosin II subfragment 1 decoration. Planta 228, 891–896 (2008). https://doi.org/10.1007/s00425-008-0802-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00425-008-0802-5