Nuclear Localization of Lectin Receptors of Central Cells of Nicotiana tabacum L

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.