Sugar composition of pollen grain and pollen tube cell walls

1981 ◽  
Vol 20 (5) ◽  
pp. 981-984 ◽  
Author(s):  
Norio Nakamura ◽  
Hiroshi Suzuki
2017 ◽  
Vol 176 (3) ◽  
pp. 1981-1992 ◽  
Author(s):  
Tohnyui Ndinyanka Fabrice ◽  
Hannes Vogler ◽  
Christian Draeger ◽  
Gautam Munglani ◽  
Shibu Gupta ◽  
...  

2014 ◽  
Vol 115 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Flavien Dardelle ◽  
François Le Mauff ◽  
Arnaud Lehner ◽  
Corinne Loutelier-Bourhis ◽  
Muriel Bardor ◽  
...  
Keyword(s):  

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 249
Author(s):  
Weimiao Liu ◽  
Liai Xu ◽  
Hui Lin ◽  
Jiashu Cao

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.


The development of the male gametophyte of Taxus baccata has been studied over a period of 20 weeks, from germination of the microspore in February to spermatogenesis in July. A few days after germination the microspore nucleus divides and a transverse wall forms at the equator cutting off the small generative cell and a large tube cell. The latter immediately begins to expand to form the pollen tube. The first division thus establishes the polarity of the gametophyte and the generative cell is regarded as proximal. The transverse wall is ephemeral, and within six weeks it has disappeared. The nucleus of the generative cell divides while still at the proximal pole. The two daughter nuclei are unequal in size, but they remain associated and together move distally. The larger nucleus eventually becomes the nucleus of the spermatogenous cell, and the smaller the sterile nucleus. The spermatogenous cell acquires a distinctive cytoplasm and becomes surrounded by a wall which arises de novo . The nucleus of the spermatogenous cell enlarges, but always remains towards one side of the cell so that at mitosis the spindle is contained within one hemisphere. After division the wall of the spermatogenous cell is ruptured and the two sperms are released as naked nuclei of equal size. The cytoplasm of the spermatogenous cell degenerates as it enters the tube, but remains recognizable until fertilization.


1987 ◽  
Vol 52 (4) ◽  
pp. 996-1001 ◽  
Author(s):  
R. F. McFEETERS ◽  
L. A. LOVDAL

2014 ◽  
Vol 65 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
Renata Śnieżko ◽  
Krystyna Winiarczyk

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.


1986 ◽  
Vol 86 (1) ◽  
pp. 1-8
Author(s):  
J. HESLOP-HARRISON ◽  
Y. HESLOP-HARRISON ◽  
M. CRESTI ◽  
A. TIEZZI ◽  
F. CIAMPOLINI

The cytoplasm of the vegetative cell of the ungerminated pollen grain of Endymton non-scriplus and other angiosperm species contains numerous fusiform bodies sometimes exceeding 15μm in length and 2.5 μm in width, which bind fluorescent-labelled phalloidin and are likely therefore to constitute a storage form of actin. The bodies are dispersed during the activation of the pollen, being replaced by aggregates of slender phalloidin-binding fibrils, which converge towards the germination apertures and are present in the emerging pollen tube. The storage bodies appear to be homologous with crystalline-fibrillar structures, shown in an earlier paper to be abundantly present in the vegetative cells of Nicotiana pollen. These are composed of massive aggregates of linearly disposed units with individual widths of 4–7 nm, probably to be interpreted as actin microfilaments. Vegetative-cell protoplasts from mature but ungerminated pollen disrupted in osmotically balancing medium release extended phalloidin-binding fibrils of a kind not observed in the intact grain. It is suggested that these are derived by the rapid dissociation of the compact actin storage bodies present in the vegetative cell at this stage of development.


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