Structural and organizational changes of the vegetative cell in Amaryllis vittata Ait. during such dynamic processes of pollen as hydration, activation and germination have been examined with electron microscopy. The ...Structural and organizational changes of the vegetative cell in Amaryllis vittata Ait. during such dynamic processes of pollen as hydration, activation and germination have been examined with electron microscopy. The mature pollen grain is composed of such organelles as plastids, mitochondria,endoplasmic reticulum, dictyosomes and lipid bodies which are in their resting state. Microfilaments appear as aggregates. After pollen activation, however,the organelles undergo great changes in number and shape: the lamellae of plastids and the cristae of mitochondria increase conspicuously in number, the cisternae of the endoplasmic reticulum become narrower; the dictyosomes produce vesicles actively the lipid bodies become degraded and the microfilament aggregates disperse. Cortical microtubules and spiny vesicles appear in the cytoplasm after germination of the pollen tube. No apparent structural changes of the organelles were noticed any longer during this period and microfilaments are distributed throughout the entire pollen tube as a three-dimensional network.展开更多
Fluorescein isothiocyanate (FITC) conjugated concanavalin agglutinin (Con A), wheat germ agglutinin (WGA) and soybean agglutinin (SBA) were used as probes to localize their specific receptors on the plasma membrane of...Fluorescein isothiocyanate (FITC) conjugated concanavalin agglutinin (Con A), wheat germ agglutinin (WGA) and soybean agglutinin (SBA) were used as probes to localize their specific receptors on the plasma membrane of generative cells (GCs) isolated from Vicia faba L., Iris tectorium Maxim. and Hippeastrum vittatum Herb. It is a further investigation on possible distributive dynamic of lectin receptors during the developmental process from generative cells to sperm cells. In the present study, all the three lectin receptors were found on the surface of generative cells of V faba and I. tectorium. However, on generative cells of H vittatum only Con A and WGA, but not SBA receptors were observed. The same lectin receptors on the generative cells from different species showed various distribution patterns. The distribution of various lectin receptors on the same generative cells also showed different characteristics. Lectin receptors were totally absent on some generative cells of all three investigated species. Polar distribution of lectin receptors was observed on tailed generative cells. The findings offer important clues to investigate sperm cell function and possible sperm dimorphism of surface glycoprotein.展开更多
文摘Structural and organizational changes of the vegetative cell in Amaryllis vittata Ait. during such dynamic processes of pollen as hydration, activation and germination have been examined with electron microscopy. The mature pollen grain is composed of such organelles as plastids, mitochondria,endoplasmic reticulum, dictyosomes and lipid bodies which are in their resting state. Microfilaments appear as aggregates. After pollen activation, however,the organelles undergo great changes in number and shape: the lamellae of plastids and the cristae of mitochondria increase conspicuously in number, the cisternae of the endoplasmic reticulum become narrower; the dictyosomes produce vesicles actively the lipid bodies become degraded and the microfilament aggregates disperse. Cortical microtubules and spiny vesicles appear in the cytoplasm after germination of the pollen tube. No apparent structural changes of the organelles were noticed any longer during this period and microfilaments are distributed throughout the entire pollen tube as a three-dimensional network.
文摘Fluorescein isothiocyanate (FITC) conjugated concanavalin agglutinin (Con A), wheat germ agglutinin (WGA) and soybean agglutinin (SBA) were used as probes to localize their specific receptors on the plasma membrane of generative cells (GCs) isolated from Vicia faba L., Iris tectorium Maxim. and Hippeastrum vittatum Herb. It is a further investigation on possible distributive dynamic of lectin receptors during the developmental process from generative cells to sperm cells. In the present study, all the three lectin receptors were found on the surface of generative cells of V faba and I. tectorium. However, on generative cells of H vittatum only Con A and WGA, but not SBA receptors were observed. The same lectin receptors on the generative cells from different species showed various distribution patterns. The distribution of various lectin receptors on the same generative cells also showed different characteristics. Lectin receptors were totally absent on some generative cells of all three investigated species. Polar distribution of lectin receptors was observed on tailed generative cells. The findings offer important clues to investigate sperm cell function and possible sperm dimorphism of surface glycoprotein.
