Proline-rich Extensin-like Receptor Kinases PERK5 and PERK12 are involved in Pollen Tube Growth

AbstractBackgroundCell wall integrity plays an essential role during polarized cell growth typical of pollen tubes and root hairs. Proline-rich Extensin-like Receptor Kinases (PERK) belong to the hydroxyproline-rich glycoprotein (HRGP) superfamily of cell surface glycoproteins.ResultsHere, we identified two PERKs from Arabidopsis thaliana, PERK5 and PERK12 highly expressed in mature pollen. Pollen tube growth was impaired in the single and double perk5-1 perk12-1 loss of function mutants, with a moderate impact on seed production. When the segregation of self- and reciprocal-crosses of the perk5-1, perk5-2 and perk12-1 single mutants, and reciprocal-crosses of the perk5-1 perk12-1 double mutant were carried out, a male gametophytic defect was found, indicating that perk5-1 and perk12-1 mutants carry defective pollen tubes, resulting in deficient pollen transmission. Furthermore, double perk5-1 perk12-1 mutants show excessive accumulation of pectins and cellulose at the cell wall pollen of the tube tip. In addition, an upregulation of cytoplasmic ROS levels were detected by using 2,7-dichlorofluorescein diacetate probe (H2DCF-DA), and in agreement, similar results were obtained with HyPer, a genetically encoded YFP-based radiometric sensor, which is used to follow the production of hydrogen peroxide (H2O2). Single and double perk5-1 perk12-1 mutants show higher levels of cytoplasmic H2O2 in their pollen tube tips.ConclusionsTaken together, our results suggest that PERK5 and PERK12 are necessary for proper pollen tube growth highlighting their role on cell wall assembly and ROS homeostasis.

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

Horticulture Research ◽

10.1038/s41438-021-00578-z ◽

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.

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

Horticultural Science ◽

10.17221/219/2012-hortsci ◽

2013 ◽

Vol 40 (No. 2) ◽

pp. 65-71 ◽

Cited By ~ 3

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.      

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

New Phytologist ◽

10.1111/nph.17391 ◽

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

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Pollen Tube Growth in Culture. I. Control of Morphology and Generative Nucleus Division in Cultured Pollen Tubes of Nicotiana

Angiosperm Pollen and Ovules ◽

10.1007/978-1-4612-2958-2_26 ◽

1992 ◽

pp. 162-167 ◽

Cited By ~ 4

Author(s):

M. Read ◽

A. Bacic ◽

A. E. Clarke

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Tubes ◽

Tube Growth ◽

Generative Nucleus

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

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1996.017 ◽

2014 ◽

Vol 65 (1-2) ◽

pp. 101-105 ◽

Cited By ~ 1

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.

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The site of action of the crossability genes (Kr 1, Kr 2) between Triticum and Secale. I. Pollen germination, pollen tube growth, and number of pollen tubes

Euphytica ◽

10.1007/bf00023204 ◽

1980 ◽

Vol 29 (3) ◽

pp. 571-579 ◽

Cited By ~ 42

Author(s):

B. S. Jalani ◽

J. P. Moss

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Germination ◽

Pollen Tubes ◽

Tube Growth ◽

Site Of Action

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Exocyst mutants suppress pollen tube growth and cell wall structural defects of hydroxyproline O‐arabinosyltransferase mutants

The Plant Journal ◽

10.1111/tpj.14808 ◽

2020 ◽

Vol 103 (4) ◽

pp. 1399-1419

Author(s):

Steven Beuder ◽

Alexandria Dorchak ◽

Ashwini Bhide ◽

Svenning Rune Moeller ◽

Bent L. Petersen ◽

...

Keyword(s):

Cell Wall ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Tube Growth ◽

Structural Defects

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

Plants ◽

10.3390/plants8060156 ◽

2019 ◽

Vol 8 (6) ◽

pp. 156 ◽

Cited By ~ 4

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.

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