Fig 2 - uploaded by Meng-xiang Sun
Content may be subject to copyright.
Comparison of fluorescence intensity among different isolated female cells labeled by FITC-WGA in Torenia fournieri. Each value in this figure is the average intensity of 10 cells selected randomly. The comparison is made under the same condition of 500 μg/ml WGA dissolved in 13% mannitol and 60 min incubation. White columns represent the fluorescence value of the cell indicated. Black columns represent the value (= 0) of the control of corresponding cells. The error bars indicate the standard deviation from the means of ten independent experiments.
Source publication
The interaction between lectins and their specific binding sites is believed to play a
critical role in fertilization in animals and some lower plants. However, for higher
plants there is no information on lectins or their binding sites related to female
gametes and fertilization. The present work was designed as a first attempt to reveal
the gener...
Context in source publication
Context 1
... signal. The signal on the synergid was stronger than that on the egg cell (Fig. 1). Among 90 central cells, 42 synergids, and 31 egg cells incubated with FITC-WGA, 90% of cells were clearly labeled and showed binding site distribution similar to the patterns of FITC-Con A labeling (Pl. I, 5b), but the fluorescence intensity was much lower (Fig. 2) than that labeled by FITC-Con A. Some fluores- cent patches were often found on the membrane of labeled ...
Similar publications
We report a fluorescence resonance energy transfer (FRET) system in which the fluorescent donor is fluorescein isothiocyanate (FITC) dye and the fluorescent acceptor is CdTe quantum dot (QDs). Based on FRET quenching theory, we designed a method to detect the concentration of silver ions (Ag(+) ). The results revealed a good linear trend over Ag(+)...
Background and objectives:
Residual platelet reactivity in patients who are taking clopidogrel is commonly measured with VerifyNow assay, which is based on the principle of light transmission aggregometry. However, to evaluate the residual platelet reactivity, it would be more accurate if the reactivity of platelet glycoprotein (GP) IIb/IIIa is di...
In this work, the preparation of novel calcium citrate (CaCit) nanoparticles (NPs) has been disclosed and the use of these NPs as “Trojan” carriers has been demonstrated. The concentration ratio between calcium ions and citrate ions was optimized, yielding spherical NPs with size in the range of 100–200 nm. Additionally, a fluorescent dye, fluoresc...
Protein nanocages resemble natural biomimetic carriers and can be engineered to act as targeted delivery systems, making them an attractive option for various drug delivery and biomedical applications. Our research investigated the genetic link of a specific anti-HER2 peptide (LTVSPWY) to the exposed N-terminal region of the maize (Zea mays) ferrit...
Fluorescein isothiocyanate (FITC) functionalized Ag/SiO2/SiO2 core–shell (CS) nanoparticles (NPs) and nanorods (NRs) are synthesized by chemical method to perform the fluorescence detection of Fe³⁺ in aqueous medium. The Fe³⁺ ion sensing is performed on the basis of metal-enhanced fluorescence and subsequent fluorescence quenching of fluorophore (f...
Citations
... Tobacco plant ovules were dissected from ovaries and placed into an enzyme solution composed of 13% mannitol, 1% cellulase R-10 and 0.8% macerozyme R-10, pH 5.7, and incubated for 3 h with agitation. The enzymes have been tested and confirmed that they do not influence the distribution and binding ability of lectin binding sites (Burgess & Linstead, 1976;Walko et al ., 1987;Sun et al ., 2002a;Fang et al ., 2003). Three washes in 13% mannitol were then performed to remove any remaining enzymes. ...
... Both types of cells yielded the same fluorescence distribution pattern in situ , as was observed for isolated female cells (Fig. 3, panel 3b). As previously reported, enzymatic treatment did not noticeably change the distribution of lectin binding sites (Burgess & Linstead, 1976;Walko et al ., 1987;Fang et al ., 2003). Furthermore, some egg cells and central cells were placed in 1% paraformaldehyde dissolved in 9% mannitol for fast surface fixation immediately after isolation. ...
The presence of mosaicism in the organization of concanavalin agglutinin (Con A) binding sites on murine egg cells was first reported 30 year ago. This discovery has triggered extensive studies into the roles of glycoproteins in gamete interactions in animals. This report comprises the first account of the existence of the mosaicism in higher plants. The distribution of Con A binding sites on both egg cells and central cells of tobacco (Nicotiana tabacum) was found to be polar and apparently determined by the location of the nucleus of the cell. On central cells, Con A binding sites were distributed on the section of the plasma membrane surface near the nucleus. By contrast, the binding sites on egg cells were concentrated away from the nucleus. Therefore, polarity of the plasma membrane component of female cells was confirmed for the first time. It is proposed that such polarized ConA binding sites could be involved in sperm recognition.
... Interactions of lectins, especially Con A, with their binding sites were also reported to be involved in the recognition of pollen and stigma in higher plants (Golynskaya et al., 1976; Knox et al., 1976; Clarke et al., 1979; Kovaleva et al., 1999 ). In our previous studies, several important LBSs were found on the membrane of sexual cells in maize and Torenia fournieri (Sun et al., 2002 a, b; Fang et al., 2003). However, whether and how they play a role in the fertilization process is still unknown. ...
... Plants of Torenia fournieri L. were grown in a greenhouse under controlled conditions (Fang et al., 2003 ). Freshly opened stigmata were hand-pollinated with fresh pollen 2 days after anthesis . ...
The binding site distribution of concanavalin agglutinin (Con A) and wheat germ agglutinin (WGA) on embryo sacs at various developmental stages of Torenia fournieri L was studied by using a cooled Charge Coupled Device (CCD) and fluorescent Con A and WGA probes. The distribution patterns of Con A and WGA binding sites on embryo sacs changed during the fertilization process. The fluorescent signal indicating Con A binding sites was distributed evenly on the surface of the embryo sac wall before anthesis, was much denser on the micropylar end of the embryo sac wall and looked like a corona on the day of anthesis. After pollination, stronger fluorescence was present on the micropylar end of the embryo sac wall and the filiform apparatus (FA), showing an obvious polar distribution. When the pollen tube entered the embryo sac and reached a synergid, the fluorescence was still concentrated on the micropylar end and FA, and started to appear on the synergid. After fertilization, the polar distribution of the fluorescence gradually disappeared and an even distribution pattern was observed again on the embryo sac wall. These results revealed that the dynamic distribution of Con A binding sites was temporally coupled with the process of fertilization. WGA binding site distribution on the embryo sac was also investigated and showed a simple pattern but also regularly changed during the process of fertilization. The variation of these lectin binding sites during the fertilization process suggests that lectin binding site interactions may play a role in the process.
Nucleus is the largest and the most important organelle of eukaryotic cells. Data concerning lectin receptor distribution on nucleus of sexual cells in angiosperms are not available yet. Central cells of tobacco were isolated and fixed and the reactions of female cell nucleus to fluorescein isothiocyanate conjugated concanavalin agglutinin (FITC-Con A) and wheat germ agglutinin (WGA) were investigated by cooled CCD combined with CoolSNAP CCD. Result indicated that nucleus of central cells reacted positively to lectins. It was further found that Con A receptors mainly distributed on the nuclear envelope of the central cells. However, WGA receptors were concentrated on the two nucleoli of the central cells. Finally, relation of glycoprotein distribution with material importing into and exporting from nucleus through the nuclear pore complex was discussed. Possible role of lectin receptors on mediating karyogamy of female cell and male cell was discussed as well.
To investigate the relation between fertilization and lectin receptor distribution, fluorescein isothiocyanate (FITC) conjugated Canavalia ensiformis agglutinin (Con A) and Triticum vulgaris agglutinin (WGA) were applied as markers to localize Con A and WGA receptors on plasma membrane of female cells in tobacco before and after fertilization by use of single cell manipulation and cooled-CCD as well. Results illustrated that polarized distribution of Con A receptor before fertilization changed to uniform after fertilization on plasma membrane of central cell and egg cell. And WGA receptors were present on the surface membrane of unfertilized female cells, but they were absent on that of fertilized female cells. So fertilization induced changes in distribution patterns of lectin receptors and composition of glycoconjugates and might therefore induce molecular modifications of plasma membrane of female cells.
Generative cells and sperm cells of tobacco were isolated and labeled by fluorescein isothiocyanate conjugated concanavalin agglutinin (FITC–Con A), wheat germ agglutinin (FITC–WGA) and soybean agglutinin (FITC–SBA) to compare lectin binding site (LBS) distributive patterns between generative cells and sperm cells, and between a pair of sperm cells from the same pollen tube. With the help of cooled charge couple device (CCD) and confocal microscope, Con A binding sites were found on the surface of 96% generative cells and 91% sperm cells. WGA binding sites were also detected on plasma membrane of generative cells and inner plasma membrane of vegetative cells and the crosswall of male germ unit (MGU), but it was hardly found on most of sperm cell surface. No soybean agglutinin (SBA) binding sites were detected on the plasma membrane of both generative cells and sperm cells. The experiment revealed that LBSs on the membrane surface of germ cell were reorganized or modified during the development from generative cell to sperm cell, indicating sperm formation might couple with its function specialization. The possible dimorphism on surface glycoprotein distribution of sperm cells was not confirmed in tobacco in this experiment since sperm cells derived from the same generative cell could be both labeled or not labeled at all by FITC–Con A. Based on the finding in present work and our former reports, we proposed that there might be functional difference of sperm in the population of living sperms of higher plants.
