scholarly journals NETWORKED2‐Subfamily Proteins Regulate the Cortical Actin Cytoskeleton of Growing Pollen Tubes and Polarised Pollen Tube Growth

2021 ◽  
Author(s):  
Patrick Duckney ◽  
Johan T. Kroon ◽  
Martin R. Dixon ◽  
Timothy J. Hawkins ◽  
Michael J. Deeks ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Actin Cytoskeleton ◽  
Pollen Tube Growth ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Cortical Actin

scholarly journals Hyperoside promotes pollen tube growth by regulating the depolymerization effect of actin-depolymerizing factor 1 on microfilaments in okra

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Biying Dong ◽  
Qing Yang ◽  
Zhihua Song ◽  
Lili Niu ◽  
Hongyan Cao ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Actin Depolymerizing Factor ◽  
Specific Mechanism ◽  
Promoting Effect ◽  
New Research

AbstractMature pollen germinates rapidly on the stigma, extending its pollen tube to deliver sperm cells to the ovule for fertilization. The success of this process is an important factor that limits output. The flavonoid content increased significantly during pollen germination and pollen tube growth, which suggests it may play an important role in these processes. However, the specific mechanism of this involvement has been little researched. Our previous research found that hyperoside can prolong the flowering period of Abelmoschus esculentus (okra), but its specific mechanism is still unclear. Therefore, in this study, we focused on the effect of hyperoside in regulating the actin-depolymerizing factor (ADF), which further affects the germination and growth of pollen. We found that hyperoside can prolong the effective pollination period of okra by 2–3-fold and promote the growth of pollen tubes in the style. Then, we used Nicotiana benthamiana cells as a research system and found that hyperoside accelerates the depolymerization of intercellular microfilaments. Hyperoside can promote pollen germination and pollen tube elongation in vitro. Moreover, AeADF1 was identified out of all AeADF genes as being highly expressed in pollen tubes in response to hyperoside. In addition, hyperoside promoted AeADF1-mediated microfilament dissipation according to microfilament severing experiments in vitro. In the pollen tube, the gene expression of AeADF1 was reduced to 1/5 by oligonucleotide transfection. The decrease in the expression level of AeADF1 partially reduced the promoting effect of hyperoside on pollen germination and pollen tube growth. This research provides new research directions for flavonoids in reproductive development.

scholarly journals Testing of self-(in)compatibility in apricot cultivars from European breeding programmes

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška
Keyword(s):  
Fluorescence Microscopy ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Reliable Method ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Breeding Programmes

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      

scholarly journals Pollen tube incompatibility reaction on the stigma in selfpollinated Sinapis alba L.

2014 ◽  
Vol 65 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
Renata Śnieżko ◽  
Krystyna Winiarczyk
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Sinapis Alba ◽  
Pollen Grain ◽  
Tube Growth ◽  
Sinapis Alba L ◽  
Growth Changes ◽  
Incompatibility Reaction

After selfpollination of <em>Sinapis alba</em> L. pollen tubes growth is inhibited on the stigma. The pollen grains germinate 3-4 hours after pollination. The pollen give rise to one or more pollen tubes. They grow along the papillae. In the place of contact between the papilla and pollen tube the pellicula is digested. Then the direction of pollen tube growth changes completely. Pollen tubes grow back on the exine of their own pollen grain, or turn into the air. The pollen tubes growth was inhibited in 6-8 hours after selfpollination. After crosspollination usually there is no incompatibility reaction.

scholarly journals Signaling in Pollen Tube Growth: Beyond the Tip of the Polarity Iceberg

Plants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 156 ◽  
Author(s):  
Nolan Scheible ◽  
Andrew McCubbin
Keyword(s):  
Pollen Tube ◽  
Signaling Pathways ◽  
Pollen Tube Growth ◽  
Tip Growth ◽  
Holistic Approach ◽  
Pollen Tubes ◽  
Small Gtpase ◽  
Tube Growth ◽  
Concerted Action ◽  
Current State

The coordinated growth of pollen tubes through floral tissues to deliver the sperm cells to the egg and facilitate fertilization is a highly regulated process critical to the Angiosperm life cycle. Studies suggest that the concerted action of a variety of signaling pathways underlies the rapid polarized tip growth exhibited by pollen tubes. Ca2+ and small GTPase-mediated pathways have emerged as major players in the regulation of pollen tube growth. Evidence suggests that these two signaling pathways not only integrate with one another but also with a variety of other important signaling events. As we continue to elucidate the mechanisms involved in pollen tube growth, there is a growing importance in taking a holistic approach to studying these pathways in order to truly understand how tip growth in pollen tubes is orchestrated and maintained. This review considers our current state of knowledge of Ca2+-mediated and GTPase signaling pathways in pollen tubes, how they may intersect with one another, and other signaling pathways involved. There will be a particular focus on recent reports that have extended our understanding in these areas.

Malus domestica ADF1 severs actin filaments in growing pollen tubes

2017 ◽  
Vol 44 (4) ◽  
pp. 455 ◽  
Author(s):  
Qing Yang ◽  
ShengNan Wang ◽  
ChuanBao Wu ◽  
QiuLei Zhang ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Actin Cytoskeleton ◽  
Malus Domestica ◽  
Pollen Tube Growth ◽  
Actin Filaments ◽  
Germination Rate ◽  
Tube Growth ◽  
Sequence Alignments ◽  
Gene Encoding ◽  
Domain Structures

A dynamic actin cytoskeleton is essential for pollen tube growth and germination. However, the molecular mechanism that determines the organisation of the actin cytoskeleton in pollen remains poorly understood. ADF modulates the structure and dynamics of actin filaments and influences the higher-order organisation of the actin cytoskeleton in eukaryotic cells. Members of the ADF family have been shown to have important functions in pollen tube growth. However, the role of this gene family remains largely unknown in apple (Malus domestica Borkh.). In this study, we identified seven ADFs in the apple genome. Phylogenetic analysis showed that MdADF1 clusters with Arabidopsis thaliana (L.) Heynh. AtADF7, ADF8, ADF10 and AtADF11. We performed sequence alignments and analysed the domain structures of the seven MdADF proteins and identified the chromosome locations of the encoding genes. We cloned the gene encoding MdADF1 from ‘Ralls Janet’ apple and found that it was strongly expressed in pollen. Biochemical assays revealed that MdADF1 directly bound to and severed F-actin under low Ca2+ conditions. We demonstrated that knockdown of MdADF1 inhibited pollen tube growth and reduced the pollen germination rate, but rendered the pollen insensitive to treatment with Latrunculin B, an actin depolymerising agent. Taken together, our results provide insight into the function of MdADF1 and serve as a reference for studies of ADF in other plants.

scholarly journals Pollen Viability and Vigor in Hybrid Southern Highbush Blueberries (Vaccinium corymbosum L. ×spp.)

HortScience ◽  
1992 ◽  
Vol 27 (5) ◽  
pp. 425-427 ◽  
Author(s):  
Gregory A. Lang ◽  
E. James Parrie
Keyword(s):  
Pollen Tube ◽  
Growth Rates ◽  
Pollen Tube Growth ◽  
Pollen Viability ◽  
Pollen Tubes ◽  
Vaccinium Corymbosum ◽  
Tube Growth ◽  
Multiple Pollen ◽  
Southern Highbush

Pollen from six southern highbush blueberry cultivars derived from Vaccinium corymbosum L. and one or more other species (V. darrowi Camp, V. ashei Reade, and V. angustifolium Aiton) was incubated on nutrient agar to determine tetrad viability, pollen tube growth rates, and incidence of multiple pollen tube germinations. `Avonblue' pollen had a significantly lower tetrad germination percentage than `Georgiagem', `Flordablue', `Sharpblue', `Gulfcoast', or `O'Neal', all of which had >90% viable tetrads. The in vitro growth rate of `O'Neal' pollen tubes was significantly higher than the growth rates of `Sharpblue' and `Georgiagem pollen tubes. Of those tetrads that were viable, more than two pollen tubes germinated from 83% and 91% of the `Gulfcoast' and `Sharpblue' tetrads, respectively, while only 11% of the `Flordablue' tetrads produced more than two pollen tubes. The total number of pollen tubes germinated per 100 tetrads ranged from 157 (`Flordablue') to 324 (`Sharpblue'), resulting in actual pollen grain viabilities ranging from 39% to 81%. Genetic differences in pollen vigor, as indicated by pollen viability, pollen tube growth rates, and multiple pollen tube germinations, may influence blueberry growers' success in optimizing the beneficial effects of cross-pollination on fruit development.

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