Stipe Cell Research Articles

Sequential production of enzymes and basidiospore formation in fruiting bodies of Coprinus macrorhizus

The production of NADP-dependent glutamate dehydrogenase was initiated at the stage of first meiotic prophase in pileus cells but not in stipe cells of dikaryotic and monokaryotic fruiting bodies in Coprinus macrorhizus. The production of chitinase and glucanases assayed with laminarin and lichenan was observed after the completion of meiosis only in pileus cells. The light conditions that were effective for the delay or inhibition of cellular events in the pileus cells were also effective for the delay or inhibition of enzyme production. But all sporeless mutants tested, which were defective at the various stages of basidiospore formation, produced the normal levels of these enzymes. The results indicate that the sequential production of enzymes and cellular events leading to basidiospore formation in pileus cells are independent from each other.

Stipe elongation during basidiocarp maturation in Coprinus macrorhizus: Changes in polysaccharide composition of stipe cell wall during elongation

Stipe elongation during basidiocarp maturation in Coprinus macrorhizus: Changes in polysaccharide composition of stipe cell wall during elongation

Changes in Cell Size and Nuclear Number During Elongation ofFlammulina VelutipesFruitbodies

SUMMARY Flammulina velutipes fruitbodies were grown on nutrient-supplemented poplar sawdust. Cells in the middle and tip of the stipe became longer with increasing fruitbody length, but cells at the base ceased to elongate when fruitbodies reached 2-3 cm. Cell width also increased in elongating stipes. Elongation of cells of the middle region accelerated at the onset of rapid stipe growth, continued at maximum rate (110 /m/day) for three-quarters of that phase, and had almost ceased when the rate of stipe growth declined. Cells in the apical region of the stipe elongated at only about one-seventh the rate of the middle cells during rapid stipe elongation. The stipe growth zone reached its maximum length during the latter phase of rapid stipe elongation, and then became shorter and restricted to the upper stipe. Cell elongation in the middle and upper middle stipe regions accounted for most of the stipe elongation but this was accompanied by cell divisions. The number of stipe cells in a row almost quadrupled between the primordium stage and the onset of rapid elongation and increased by 40% thereafter. Stipe and pileus cells were usually binucleate in primordia. Subsequently, cells of the stipe and pileus context became multinucleate but those of the lamellar trama remained binucleate. The number of nuclei in stipe cells almost doubled during early fruitbody development, and increased to a mean of 9.1-9.2 in the middle and tip cells during rapid stipe elongation. In basal cells the nuclear number reached its maximum before the onset of rapid growth. No correlation was found between nuclear number and cell size.

Studies onSargassum II. Quantitative ultrastructural changes in differentiated stipe cells during wound regeneration and regrowth

Quantitative electron micrograph analytical techniques were used to study cytological changes associated with the process of dedifferentiation and redifferentiation in mature, specialized cells of the stipe in the brown algaSargassum filipendula following wounding. Early cytological changes associated with this process appear to be those involved with formation of a protective layer of material at the wound surface. An increase in the volume of cytoplasm occupied by mitochondria, dictyosomes, and type A and B vesicles was evident by three days postwound. Cytoplasmic volume occupied by chloroplasts decreased during the early stages of wound reaction while the development of internal membranes (thylakoids) in these organelles increased. Cells at the cut surface eventually differentiated into one of two types of tissues: 1. A wound surface epidermal layer similar in cytological aspect to the epidermal layers of the intact and regenerated plant. 2. A meristematic “regeneration bud” from which developed the blade-like regeneration growth. The morphology and anatomy of the tissues of the regeneration blade resembled those of the blade of the intact plant rather than those of the stipe from which it originated. Percent difference values were obtained by comparing cytological features of the tissues from the regeneration blade with those of the intact stipe and blade. The comparisons supported previously obtained data indicating that the regeneration blade should be considered as a typical blade organ rather than a morphological variant of the stipe. Results of this study raises questions about possible physiological differences which may exist between stipe and blade organs in this plant.

A DEVELOPMENTAL STUDY OF EXTRAFLORAL NECTARIES IN SLIPPER SPURGE (PEDILANTHUS TITHYMALOIDES, EUPHORBIACEAE)

Slipper spurge (Pedilanthus tithymaloides) bears one or two stalked extrafloral nectaries on either side of the leaf base and one at the leaf tip. The mature nectary is differentiated into multicellular zones: head, neck, and stipe. The nectary arises as a small group of meristematic cells with densely staining cytoplasm and nuclei. The columnar secretory cells show changes in their chemical nature at different developmental stages of the nectary. There is a basipetal sequence in the development and decay of the tissues in the nectary. Decay of the nectary begins at the head, abscission occurs at the line between stipe and neck regions, and the scars of the fallen nectaries are left when the stipe cells also collapse.

A Development Study of Extrafloral Nectaries in Slipper Spurge (Pedilanthus tithymaloides, Euphorbiaceae)

Slipper spurge (Pedilanthus tithymaloides) bears one or two stalked extrafloral nectaries on either side of the leaf base and one at the leaf tip. The mature nectary is differentiated into multicellular zones: head, neck, and stipe. The nectary arises as a small group of meristematic cells with densely staining cytoplasm and nuclei. The columnar secretory cells show changes in their chemical nature at different developmental stages of the nectary. There is a basipetal sequence in the development and decay of the tissues in the nectary. Decay of the nectary begins at the head, abscission occurs at the line between stipe and neck regions, and the scars of the fallen nectaries are left when the stipe cells also collapse.

Intracellular appearance of mushroom virus in fruiting bodies and basidiospores of Agaricus bisporus

Virus particles of 34 nm diameter were detected in ultrathin sections of cap, stipe, and basidiospores of Agaricus bisporus (Lange) Sing. These particles formed dense aggregates in vegetative mycelium, but occurred dispersed and often abundantly in the cytoplasm and sometimes in vacuoles of fruiting bodies. In basidiospores 34 nm virus particles were found grouped together in small vacuoles and occasionally in the spore cytoplasm. Virus particles of 19 × 50 nm were seldom observed in cytoplasm of the stipe. Isometric particles of 25 nm, resembling ribosomes, were found in disarranged cells of the cap of mushrooms known to contain many 25 nm virus particles. These isometric particles occurred in vacuoles, free or clumped together and membrane bound, or were aggregated into membrane-limited electron-dense bodies. In such cells many 34 nm particles were also observed. In cap and stipe cells of the same mushrooms helices, thought to consist of ribosomes, were often found. Virus particles of 34 nm diameter were observed in dolipores, which implies cell to cell translocation. The means of spread of mushroom virus disease by hyphal anastomosis and by spores from diseased mushrooms were confirmed. No viruslike particles, electron-dense bodies, or helices were found in tissue or spores from healthy mushrooms.