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

After selfpollination of Sinapis alba 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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Determination of cardinal temperatures for sugar apple ( Annona squamosa L.)

Ciência e Agrotecnologia ◽

10.1590/1413-70542016402039115 ◽

2016 ◽

Vol 40 (2) ◽

pp. 145-154 ◽

Cited By ~ 5

Author(s):

Bruno Rafael Alves Rodrigues ◽

Rayane Carneiro dos Santos ◽

Silvia Nietsche ◽

Maria Olívia Mercadante-Simões ◽

Isabella Renata Gomes da Cunha ◽

...

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Grains ◽

Pollen Grain ◽

Tube Growth ◽

Effect Of Temperature ◽

In Vitro Germination ◽

Cardinal Temperatures ◽

Germination Of Pollen

ABSTRACT The sugar apple is highly dependent on the pollination and fruit tree pollen performance is crucial for successful fertilization and fruit set. The objective of this study was to determine the cardinal temperatures for in vitro pollen grains germination and evaluate the effect of temperature on pollen tube growth of sugar apple. The experimental design was in a completely randomized with eight treatments (10, 15, 20, 25, 30, 35, 40 and 45 ºC), four replicates and each plot was constituted by two slides per parcel. The cardinal temperatures were determined by evaluating in vitro germination of pollen grains and pollen tube growth in standard culture medium. It also assessed the pollen tube growth and the percentage of germination in vitro depending on the type of pollen grain arrangement (monad, dyad, triad and tetrad). In vitro germination of pollen grains and pollen tube growth varied significantly with temperature. The maximum germination recorded (48.13%) and the maximum lengths of pollen tubes (536.45 μm) were obtained when pollen grains were cultivated at 25 ºC. The estimated cardinal temperatures were 9.7, 26.9 and 44.2 ºC. Among the pollen grain arrangements, tetrads pollen grains were observed in higher proportions, however, monads pollen grains presented higher germination percentage.

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Pollen performance and male fitness in an anemophilous, monoecious tree, Betula pendula

Canadian Journal of Botany ◽

10.1139/b04-069 ◽

2004 ◽

Vol 82 (9) ◽

pp. 1284-1291 ◽

Cited By ~ 6

Author(s):

Päivi Pietarinen ◽

Hanna-Leena Pasonen

Keyword(s):

Growth Rate ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Betula Pendula ◽

Pollen Grains ◽

Pollen Grain ◽

Tube Growth ◽

Pollen Tube Growth Rate ◽

Pollen Grain Size

Betula pendula Roth clones were examined to study the relationship between pollen grain size and pollen tube growth rate and pollen and seed performance. Two hypotheses were tested: (i) pollen donors with larger pollen grains have faster growing pollen tubes and (ii) maternal plants produce more seeds when inflorescences have been pollinated by pollen from donors with fast pollen tube growth. Pollen from 15 plants was collected, and pollen grain sizes and pollen tube growth rates were studied in vitro. Eight maternal clones were pollinated by pollen from seven paternal clones, pollen tube growth rates of the pollen donors were measured on each maternal plant, and the number and mass of the resulting seeds were analysed. There was no correlation between pollen grain size and pollen tube growth rate in vitro. Also, there was no relationship between pollen tube growth rate and the number of produced or aborted seeds. Thus, the hypothesis that larger pollen grains would have longer pollen tubes was not supported by the present study. The results of the present study do not support the idea that pollen donors with fast pollen tube growth should sire more and better seeds.Key words: Betula pendula, female choice, nonrandom abortion, pollen competition, sexual selection.

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Polyamines Involved in Regulating Self-Incompatibility in Apple

Genes ◽

10.3390/genes12111797 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1797

Author(s):

Jie Yu ◽

Baoan Wang ◽

Wenqi Fan ◽

Songbo Fan ◽

Ya Xu ◽

...

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Tubes ◽

Inhibitory Effect ◽

Tube Growth ◽

Calcium Signal ◽

Self Incompatibility ◽

Sequencing Data ◽

Incompatibility Reaction ◽

Polyamine Oxidases

Apple exhibits typical gametophytic self-incompatibility, in which self-S-RNase can arrest pollen tube growth, leading to failure of fertilization. To date, there have been few studies on how to resist the toxicity of self-S-RNase. In this study, pollen tube polyamines were found to respond to self-S-RNase and help pollen tubes defend against self-S-RNase. In particular, the contents of putrescine, spermidine, and spermine in the pollen tube treated with self-S-RNase were substantially lower than those treated with non-self-S-RNase. Further analysis of gene expression of key enzymes in the synthesis and degradation pathways of polyamines found that the expression of DIAMINE OXIDASE 4 (MdDAO4) as well as several polyamine oxidases such as POLYAMINE OXIDASES 3 (MdPAO3), POLYAMINE OXIDASES 4 (MdPAO4), and POLYAMINE OXIDASES 6 (MdPAO6) were significantly up-regulated under self-S-RNase treatment, resulting in the reduction of polyamines. Silencing MdPAO6 in pollen tubes alleviates the inhibitory effect of self-S-RNase on pollen tube growth. In addition, exogenous polyamines also enhance pollen tube resistance to self-S-RNase. Transcriptome sequencing data found that polyamines may communicate with S-RNase through the calcium signal pathway, thereby regulating the growth of the pollen tubes. To summarize, our results suggested that polyamines responded to the self-incompatibility reaction and could enhance pollen tube tolerance to S-RNase, thus providing a potential way to break self-incompatibility in apple.

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Pollen tube branching in the ovary of five species of Oenothera

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1996.019 ◽

2014 ◽

Vol 65 (1-2) ◽

pp. 111-116 ◽

Cited By ~ 3

Author(s):

Renata Śnieżko

Keyword(s):

Grain Size ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Morphology ◽

Pollen Grains ◽

Growth Direction ◽

Pollen Grain ◽

Tube Growth ◽

Oenothera Hookeri ◽

Pollen Grain Size

Flowers of Oenothera hookeri Torr. et Gray, Oe. brevistylis and Oe. lamarkiana de Vries were pollinated after anthesis by insects. Oe. biennis L., Oe. suaveolens Desf and sulfurea were selfpollinated in the buds. Pollen morphology was slightly different: Oe. hookeri have regular, triporated pollen, often germinating through two pores; in Oe. suaveolens many pollen grains had callose patches on the intine; in Oe. brevistylis tetraporated pollen were more often than in other species; in Oe. lamarckiana many pollen grains were empty; in Oe. biennis and Oe. suaveolens pollen grain size and viability varied. The pollen tube growth and fertilization were similar in 5 species and can be considered as typical for Oenothera. In the ovary pollen tubes branched and changed their growth direction. Near micropyle they formed short branches to the inner integument. In the nucellus the pollen tube became swollen.

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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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Two Expansin Genes, AtEXPA4 and AtEXPB5, Are Redundantly Required for Pollen Tube Growth and AtEXPA4 Is Involved in Primary Root Elongation in Arabidopsis thaliana

Genes ◽

10.3390/genes12020249 ◽

2021 ◽

Vol 12 (2) ◽

pp. 249

Author(s):

Weimiao Liu ◽

Liai Xu ◽

Hui Lin ◽

Jiashu Cao

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Cell Walls ◽

Root Elongation ◽

Expression Patterns ◽

Primary Root ◽

Pollen Grains ◽

Tube Growth ◽

Cell Wall Binding

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.

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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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