scholarly journals Pollen Tube Growth in Cross Combinations between Torenia fournieri and Fourteen Related Species

2007 ◽  
Vol 57 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Shinji Kikuchi ◽  
Hiroki Kino ◽  
Hiroyuki Tanaka ◽  
Hisashi Tsujimoto
1972 ◽  
Vol 14 (2) ◽  
pp. 381-389 ◽  
Author(s):  
Chi-Chang Chen ◽  
Pryce B. Gibson

Pre-fertilization barriers to hybridization of Trifolium repens L. with its related species, T. nigrescens, T. occidentale, T. hybridum, T. ambiguum, and T. uniflorum, were studied by comparing pollen germination, pollen-tube growth, and fertilization following intra- and interspecific pollinations on T. repens. Pollen of T. repens began to germinate almost immediately after being placed on the stigmas of its own species; pollen germination approached 100% in 30 min. Pollen tubes grew rapidly. Eight hours after pollination the longer tubes had entered the micropyle of the most distant ovules. Fertilization was first observed at 8 hr. All ovules were fertilized within 24 hr. In interspecific pollinations using T. repens as the pistillate parent, the time required for pollen germination was longer and the frequency of germination was lower. Pollen tubes frequently swelled, coiled, or even burst in the styles. Pollen tubes of the species more closely related to T. repens appeared to grow faster and more normally. Fertilization occurred in all interspecific crosses. The highest frequency of ovules fertilized generally occurred in the species combinations in which pollen-tube growth was most similar to the control and the lowest frequency, in the combinations in which tube growth deviated the most from the control. These observations suggest that pre-fertilization barriers are not the only causes of cross-incompatibility of T. repens with related species. Post-fertilization barriers, which prevent zygotes from developing into viable seeds, also must exist.


1989 ◽  
Vol 58 (3) ◽  
pp. 515-521 ◽  
Author(s):  
Goro OKAMOTO ◽  
Ikuo SHIBUYA ◽  
Miwa FURUICHI ◽  
Kazuo SHIMAMURA

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Biying Dong ◽  
Qing Yang ◽  
Zhihua Song ◽  
Lili Niu ◽  
Hongyan Cao ◽  
...  

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.


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.


2021 ◽  
Vol 288 ◽  
pp. 110390
Author(s):  
Radosav Cerović ◽  
Milica Fotirić Akšić ◽  
Milena Đorđević ◽  
Mekjell Meland

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