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Under a scanning microscope, leaves from tissue cultures (after 8 weeks in vitro culturing), from 1 year old regenerants and from the 100 years old donor tree were studied. More abnormalities were observed in the tissue culture compared to regenerant and donor. During tissue culture transfer rapid, leaf dehydration occurs due to defective regulation mechanisms making stomata of tissue culture stay open. Epidermis as well as stomata cells were observed already on the leaves in in vitro conditions, but they become physiologically functioning only after transfer into conditions of natural environment.
It has been shown for the first time that [3-3H]oIeanolic acid glycosides formed in the cytosol of C. officinalis leaf cells are transported to the extracellular space in the form of pentaglucoside VI (44%), whereas glucuronides derived from [3-3H]oleanolic acid 3-O-monoglucuronide (29%) as well asa part of glucosides (24%) were transported into the cell walls.
Anthocyanins are a group of water-soluble flavonoids known for their protective role against photoinhibitory and photooxidative damage to leaf cells under environmental stress. The effects of variation in light quantity on rates of anthocyanin production in foliage of Iris pumila were evaluated spectrophotometrically in a field experimental setting accomplished by shielding one half of each examined plant with a 65% neutral-density shade, whereas the other half experienced full sunlight. In unshaded leaves, the average anthocyanin level increased by 55.3% compared to their shaded counterparts. Because there was no a significant difference in the average level of pheophytin (a breakdown product of chlorophyll) between unshaded and shaded leaves, the results suggested that the elevated anthocyanin concentrations in sun-exposed foliage of I. pumila could act as a light attenuator, protecting its chloroplasts from excess high-energy quanta that would otherwise be intercepted by the chlorophylls.
Two experimental methods were used in the study. The aim of the first one was focused on a detection of Arabis mosaic nepovirus (ArMV) particles and tubules with viruses in extracts obtained from crushed leaves of bean. Second one consisted on investigation of ultrastructural changes occuring in the bean leaf tissues with symptoms caused by ArMV. Characteristic membranous inclusions in the cytoplasm were observed and described. ArMV occured either as irregularly scattered particles in the cytoplasm, crystal-like aggregates or semiconcentric and concentric layers. Not numerous but sometimes very long tubules with viruses were mainly observed near the cell wall. Protrusion of the cell wall into the protoplast very often containing viruses in the plasmodesmata were observed many times. Plasmalemmasomes were frequently situated near the cell wall.
The distribution and content of calcium ions in organelles, cytoplasm and celi walls of leaf mesophyll and epidermis of Sium latifolium air-water and terrestrial plants at various developmental stage was investigated. It was established that the relative content of Ca2+ in cells changed in relation to growth stage and environmental growth conditions. Moderate water deficit led to the increase of calcium content in chloroplasts and nucleus of palisade mesophyll, and in cell walls of adaxial epidermis of plants that were collected at flowering phase. At fruitage stage, water deficit led to the decrease of Ca2+ in chloroplasts and in cytoplasm of mesophyll cells and in cell walls of epidermis. The obtained results show that these data can be used as a basis for future studies on the mechanisms of calcium redistribution and the role of ion channels in plant cells under water deficit.
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