Mechanics of Pollen Tube Elongation: A Perspective

In Arabidopsis, as in the majority of flowering plants, developing seeds promote fruit growth. One method to investigate this interaction is to use plants with reduced seed set and determine the effect on fruit growth. Plants homozygous for a transgene designed to ectopically express a gene encoding a gibberellin-deactivating enzyme exhibit reduced pollen tube elongation, suggesting that the plant hormone gibberellin is required for this process. Reduced pollen tube growth causes reduced seed set and decreased silique (fruit) size, and this genotype is used to explore the relationship between seed set and fruit elongation. A detailed analysis of seed set in the transgenic line reveals that reduced pollen tube growth decreases the probability of each ovule being fertilised. This effect becomes progressively more severe as the distance between the stigma and the ovule increases, revealing the complex biology underlying seed fertilisation. In terms of seed-promoted fruit growth, major localised and minor non-localised components that contribute to final silique length can be identified. This result demonstrates that despite the relatively small size of the fruit and associated structures, Arabidopsis can be used as a model to investigate fundamental questions in fruit physiology.

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In vitro germination and viability of pea pollen grains after application of organic nano-fertilizers

Pesticidi i fitomedicina ◽

10.2298/pif1701061g ◽

2017 ◽

Vol 32 (1) ◽

pp. 61-65 ◽

Cited By ~ 1

Author(s):

Natalia Georgieva ◽

Ivelina Nikolova ◽

Valentin Kosev ◽

Yordanka Naydenova

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Culture Media ◽

Pollen Viability ◽

Pollen Grains ◽

Pollen Grain ◽

In Vitro Germination ◽

Pisum Sativum L ◽

Pollen Tube Elongation

The objective of this study was to evaluate the influence of two organic nanofertilizers, Lithovit and Nagro, on in vitro germination, pollen tube elongation and pollen grain viability of Pisum sativum L cv. Pleven 4. The effect of their application was high and exceeded data for the untreated control (44.2 and 47.23 % regarding pollen germination and pollen tube elongation, respectively), as well as the effect of the control organic algal fertilizer Biofa (17.5 and 27.9 %, respectively). Pollen grains were inoculated in four culture media. A medium containing 15% sucrose and 1% agar had the most stimulating impact on pea pollen grains. Pollen viability, evaluated by staining with 1% carmine, was within limits of 74.72-87.97%. The highest viability of pollen grains was demonstrated after the application of Nagro organic nano-fertlizer.

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Effect of nickel on pollen germination and pollen tube length in Arabis alpina (Brassicaceae)

Australian Journal of Botany ◽

10.1071/bt15291 ◽

2016 ◽

Vol 64 (4) ◽

pp. 302 ◽

Cited By ~ 1

Author(s):

Dolja Pavlova

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Pollen Grains ◽

Tube Length ◽

Serpentine Soils ◽

Nutritional Medium ◽

Arabis Alpina ◽

Pollen Tube Elongation ◽

Germinated Pollen ◽

Pollen Tube Length

In this work we studied and compared the toxic effect of nickel (Ni) on pollen germination and pollen tube length in Arabis alpina L. collected from serpentine and non-serpentine populations distributed in the Rila mountains, Bulgaria. Pollen grains were treated with prepared standard solutions of 100, 300, 500, and 700 μM Ni as NiCl2 in distilled water. A nutritional medium was also used to assess pollen germination. Nickel inhibited pollen germination and pollen tube elongation in both serpentine and non-serpentine plants. The percentage of germinated pollen in serpentine plants treated with Ni was higher than in non-serpentine plants but there was no difference in pollen tube elongation between groups. However, pollen tubes showed abnormalities such as coiling and swelling of the tip, or burst, and varied considerably among the samples. A complete break of pollen tube elongation is due to such abnormalities. Also, decreased pollen fertility in both populations was found. The plants from serpentines were less sensitive to (i.e. more tolerant of) elevated Ni concentrations commonly found in serpentine soils.

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Pollen‒pistil interaction in Lilium longiflorum : the role of the pistil in controlling pollen tube growth following cross- and self-pollinations

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1982.0027 ◽

1982 ◽

Vol 215 (1198) ◽

pp. 45-62 ◽

Cited By ~ 37

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Active Component ◽

Lilium Longiflorum ◽

The Self ◽

Tube Growth ◽

Self Incompatibility ◽

System A ◽

Pollen Tube Elongation

By cytophysiological methods, the self-incompatibility mechanism of the breeding system in Lilium longiflorum has been examined with particular reference to the synthesis, location and nature of the stylar factors involved in the control of pollen tube development. A ‘bioassay’ has been developed by which the effect of stylar extracts on pollen tube elongation may be investigated. With use of this system, a crude fraction of proteins from the stylar fluid has been shown to inhibit pollen tube growth only when protein fractions from ‘self’ styles are used. The proteins of this fraction have been analysed by thin-layer gel electrofocusing. Changes in the profiles thus obtained following selfing and a heat treatment known to inactivate the self-incompatibility response indicate a highly polarized glycoprotein to be an active component of the system. The various ways by which such a glycoprotein could control pollen tube elongation are considered in detail, and these events in Lilium are discussed in the light of our knowledge of other self-incompatibility systems operating in angiosperms.

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Effects of day length on pollen tube elongation, embryo formation and seed development after flowering in quinoa (Chenopodium quinoa Willd.)

Seed Science Research ◽

10.1017/s0960258518000223 ◽

2018 ◽

Vol 28 (4) ◽

pp. 272-276 ◽

Cited By ~ 1

Author(s):

Katsunori Isobe ◽

Hikaru Sugiyama ◽

Katsura Tamamushi ◽

Taito Shimizu ◽

Kana Kobashi ◽

...

Keyword(s):

Pollen Tube ◽

Seed Development ◽

Chenopodium Quinoa ◽

Early Embryo ◽

Flowering Plants ◽

Day Length ◽

Embryo Formation ◽

Pollen Tube Elongation ◽

Number Of Seeds ◽

Seed Diameter

AbstractThe objective of this study was to evaluate the effect of day length after flowering on pollen tube elongation, embryo formation and seed development. The quinoa varieties used in this study were Amarilla de Marangani (valley type) and NL-6 (sea-level type). After sowing, the quinoa plants were cultivated in growth cabinets. From sowing to flowering, plants were exposed to a 15 h day length regime. After flowering, the plants were grown under either a 15 h or 11 h day length regime. The elongation of the pollen tube and the formation of the early embryo were not inhibited in either Amarilla de Marangani or NL-6 under the 11 or 15 h day length regimes. Although growth of the embryo in NL-6 was not inhibited by the 15 h day length regime after flowering, the same was not observed in the case for Amarilla de Marangani. In Amarilla de Marangani, seed diameter at 8 and 14 days after flowering under the 11 h day length regime was larger than that of seeds grown under the 15 h day length regime. Thus, the decrease in the number of seeds in Amarilla de Marangani grown under the 15 h day length regime may be caused by the suspension of embryo growth after fertilization.

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Microtubules play a role in trafficking prevacuolar compartments to vacuoles in tobacco pollen tubes

Open Biology ◽

10.1098/rsob.180078 ◽

2018 ◽

Vol 8 (10) ◽

pp. 180078 ◽

Cited By ~ 1

Author(s):

Elisabetta Onelli ◽

Monica Scali ◽

Marco Caccianiga ◽

Nadia Stroppa ◽

Piero Morandini ◽

...

Keyword(s):

Plasma Membrane ◽

Pollen Tube ◽

Biochemical Analysis ◽

Pollen Tubes ◽

Degradation Pathways ◽

Transient Transformation ◽

Secretory Pathways ◽

Tobacco Pollen ◽

Fine Regulation ◽

Pollen Tube Elongation

Fine regulation of exocytosis and endocytosis plays a basic role in pollen tube growth. Excess plasma membrane secreted during pollen tube elongation is known to be retrieved by endocytosis and partially reused in secretory pathways through the Golgi apparatus. Dissection of endocytosis has enabled distinct degradation pathways to be identified in tobacco pollen tubes and has shown that microtubules influence the transport of plasma membrane internalized in the tip region to vacuoles. Here, we used different drugs affecting the polymerization state of microtubules together with SYP21, a marker of prevacuolar compartments, to characterize trafficking of prevacuolar compartments in Nicotiana tabacum pollen tubes. Ultrastructural and biochemical analysis showed that microtubules bind SYP21-positive microsomes. Transient transformation of pollen tubes with LAT52-YFP-SYP21 revealed that microtubules play a key role in the delivery of prevacuolar compartments to tubular vacuoles.

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Rac Homologues and Compartmentalized Phosphatidylinositol 4, 5-Bisphosphate Act in a Common Pathway to Regulate Polar Pollen Tube Growth

The Journal of Cell Biology ◽

10.1083/jcb.145.2.317 ◽

1999 ◽

Vol 145 (2) ◽

pp. 317-330 ◽

Cited By ~ 330

Author(s):

Benedikt Kost ◽

Emmanuel Lemichez ◽

Pius Spielhofer ◽

Yan Hong ◽

Kimberly Tolias ◽

...

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Intracellular Localization ◽

Small Gtpases ◽

Tube Growth ◽

Yeast Cells ◽

Common Pathway ◽

Pollen Tube Elongation ◽

Rho Family ◽

Phosphatidylinositol 4

Pollen tube cells elongate based on actin- dependent targeted secretion at the tip. Rho family small GTPases have been implicated in the regulation of related processes in animal and yeast cells. We have functionally characterized Rac type Rho family proteins that are expressed in growing pollen tubes. Expression of dominant negative Rac inhibited pollen tube elongation, whereas expression of constitutive active Rac induced depolarized growth. Pollen tube Rac was found to accumulate at the tip plasma membrane and to physically associate with a phosphatidylinositol monophosphate kinase (PtdIns P-K) activity. Phosphatidylinositol 4, 5-bisphosphate (PtdIns 4, 5-P2), the product of PtdIns P-Ks, showed a similar intracellular localization as Rac. Expression of the pleckstrin homology (PH)-domain of phospholipase C (PLC)-δ1, which binds specifically to PtdIns 4, 5-P2, inhibited pollen tube elongation. These results indicate that Rac and PtdIns 4, 5-P2 act in a common pathway to control polar pollen tube growth and provide direct evidence for a function of PtdIns 4, 5-P2 compartmentalization in the regulation of this process.

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