First evidence of a calcium transient in flowering plants at fertilization

Development ◽  
1997 ◽  
Vol 124 (15) ◽  
pp. 2867-2874 ◽  
Author(s):  
C. Digonnet ◽  
D. Aldon ◽  
N. Leduc ◽  
C. Dumas ◽  
M. Rougier
Keyword(s):  
Calcium Transient ◽  
Flowering Plants ◽  
Flowering Plant ◽  
Egg Cell ◽  
Vitro Fertilization ◽  
Zygote Development ◽  
Early Zygote ◽  
Transient Elevation ◽  
Indicator Dye

We report here the first evidence of a transient elevation of free cytosolic Ca2+ following fusion of sperm and egg cell in a flowering plant by the use of an in vitro fertilization system recently developed in maize. Imaging changes in cytosolic Ca2+ at fertilization was undertaken by egg cell loading with the fluorescent Ca2+ indicator dye fluo-3 under controlled physiological conditions. The gamete adhesion step did not induce any cytosolic Ca2+ variation in the egg cell, whereas the fusion step triggered a transient cytosolic Ca2+ rise in the fertilized egg cell, lasting several minutes. This rise occurred after the establishment of gamete cytoplasm continuity. Through these observations, we open the way to the identification of the early signals induced by fertilization in flowering plants that give rise to the calcium transient and to investigations of the role of Ca2+ during egg activation and early zygote development in plants, as has been reported for other better characterized animal and algae systems.

scholarly journals A calcium influx is triggered and propagates in the zygote as a wavefront during in vitro fertilization of flowering plants

2000 ◽  
Vol 97 (19) ◽  
pp. 10643-10648 ◽  
Author(s):  
A. F. Antoine ◽  
J.-E. Faure ◽  
S. Cordeiro ◽  
C. Dumas ◽  
M. Rougier ◽  
...  
Keyword(s):  
In Vitro Fertilization ◽  
Calcium Influx ◽  
Flowering Plants ◽  
Vitro Fertilization

Plant gametes as tools for molecular breeding

2002 ◽  
Vol 50 (3) ◽  
pp. 295-301
Author(s):  
B. Barnabás ◽  
Z. Pónya ◽  
F. Bakos ◽  
Keyword(s):  
Molecular Biology ◽  
Essential Role ◽  
Cell Activation ◽  
Molecular Breeding ◽  
Experimental Approach ◽  
Embryo Sac ◽  
Flowering Plants ◽  
Cereal Crops ◽  
Egg Cell

Sexual reproduction plays an essential role in the propagation of Angiosperms. Fertilisation takes place in the embryo sac, which is usually deeply encased in the sporophytic tissues of the ovule. In contrast to animals and primitive plants, the mechanism of egg cell activation in flowering plants has not been discovered fully because of the inaccessibility and complexity of the process of double fertilisation. However, recent advances in plant cell and molecular biology have brought new, powerful technologies to investigate and micromanipulate the reproductive cells of flowering plants including cereal crops. An experimental approach based on various micromanipulation techniques involving in vitro fertilisation (IVF) and microinjection procedures is now available in more and more laboratories. Despite some limitations this offers new possibilities to study cellular and subcellular events preceding or occurring during or after egg cell activation and early embryonic development. Recent achievements in the field of wheat egg cell micromanipulation are presented in this paper.

Isolation of protoplasts from viable egg cells of common buckwheat (Fagopyrum esculentum Moench.)

1999 ◽  
Vol 79 (4) ◽  
pp. 593-595 ◽  
Author(s):  
Sun Hee Woo ◽  
Taiji Adachi ◽  
Seung Keun Jong ◽  
Clayton G. Campbell
Keyword(s):  
In Vitro Fertilization ◽  
Embryo Sac ◽  
Fagopyrum Esculentum ◽  
Enzyme Treatment ◽  
Egg Cell ◽  
Common Buckwheat ◽  
Vitro Fertilization ◽  
Mechanical Isolation ◽  
Fagopyrum Esculentum Moench

In vitro fertilization could be useful to overcome the problem of self-incompatibility of common buckwheat. Therefore, experiments were conducted to isolate viable protoplasts from egg cells for use in vitro fertilization. Protoplasts from viable egg cells of common buckwheat were isolated by enzyme treatment followed by mechanical isolation. Incubation of ovules for up to 4 h allowed the boundary wall of the egg cells to become partially digested and the protoplasts of the egg cells came out of the micropylar or chalazal end after squashing with a mean isolation frequency of approximately 30% (6 out of 20 ovules). The egg cell protoplasts were larger than those of the synergids. Key words: Common buckwheat, Fagopyrum esculentum Moench., protoplast, egg cell solation, embryo sac

Expression of the cell cycle in sperm of Arabidopsis: implications for understanding patterns of gametogenesis and fertilization in plants and other eukaryotes

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1065-1075 ◽  
Author(s):  
W.E. Friedman
Keyword(s):  
Cell Cycle ◽  
Higher Plants ◽  
Generative Cell ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Flowering Plants ◽  
S Phase ◽  
Flowering Plant ◽  
Sperm Nuclei

The relationship between developmental events and the cell cycle was examined in sperm of Arabidopsis thaliana. Sperm of Arabidopsis rapidly enter the S (synthesis) phase of the cell cycle after inception from mitosis of the generative cell. Sperm in pollen grains within anthers continue to synthesize DNA, and at the time of pollination, contain approximately 1.5C DNA. Following pollination, sperm continue through the S phase of the cell cycle during pollen tube growth. By the time pollen tubes reach the ovary, sperm nuclei contain approximately 1.75C DNA. Just prior to double fertilization, sperm nuclei within embryo sacs contain the 2C quantity of DNA. These data indicate that molecular programs associated with the G1-S transition and the S phase of the cell cycle are expressed in sperm cells of developing pollen grains and pollen tubes in Arabidopsis. This pattern of prefertilization S phase activity in the sperm of a flowering plant stands in marked contrast to all other non-plant eukaryotes (from ciliates to yeast to sea urchins to mammals) where sperm remain in G1 during development, prior to the initiation of gametic fusion. In addition, when patterns of cell cycle activity in sperm of Arabidopsis and other flowering plants are compared, developmental analysis reveals that heterochronic alterations (changes in the relative timing of ontogenetic events) in cell cycle activity are a central cause of the diversification of patterns of gametogenesis in higher plants. Finally, comparative analysis of the patterns of cell cycle activity in Arabidopsis and other angiosperms may be used to predict which flowering plants will be amenable to development of successful in vitro fertilization techniques.

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