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In Schizaeaceae ferns, including Anemia phyllitidis, formation of antheridia is known to be induced by exogenously applied gibberellic acid. Also present studies show that GA₃ (10⁻⁵ mol·dm⁻³) modifies the development of gametophytes of Anemia phyllitidis. Simultaneously with formation of antheridia, they exhibit lower number of cells but only slightly lowered profile areas and lengths of prothalli. Growth in size of individual cells compensates for lowered division frequency. Cytophotometric measurements reveal no essential changes in the DNA content in vegetative cells of the control and GA₃-stimulated gametophytes. It remains at haploid level and therefore it is assumed that cell cycle is blocked at G1 phase. Application of GA₃ increases the total amount of proteins. CZE (Capillary Zone Electrophoresis) separation of peptides extracted from control and GA₃-treated prothalli indicates the differences in the ratio of their particular forms. In GA₃-treated gametophytes the activities of acid and basic phosphatases, contents of carbohydrates (glucose, starch), chlorophyll, the number of chloroplasts and dry mass of prothalli are increased. GA₃-intensified metabolism, evidenced in gametophytes of A. phyllitidis, may be interpreted as a stimulatory mechanism which influences metabolic pathways involved in forming, developing and maturing of male sex organs.
Ultrastructural changes of manubria of Chara vulgaris during spermiogenesis were studied. The changes (as compared to the antheridial filament proliferation stage) involve thickening of the content of secretive vesicles and changes in their consistency, the disappearance of rough endoplasmic reticulum (ER) and appearance of smooth ER, increases in the number and size of plastoglobules in plastids, condensation of mitochondria, and significant cell vacuolization. Autoradiography with 3H-fucose pulse incubation showed that during spermatogenesis it was incorporated into the manubria. Their radioactivity decreased after 2 h postincubation in nonradioactive fucose during spermiogenesis. This was not observed during proliferation of antheridial filament cells. It is suggested that polysaccharide secretion into the internal antheridial space increases during spermiogenesis, perhaps connected with the thickening of secretive vesicle content observed by electron microscopy.
Low molecular weight peptidic component extracted from maturing male sex organs of Chara tomentosa, capable of inducing increased condensation of chromosomes and profound changes in the cell cycle progression, was applied to gametophytes of Anemia phyllitidis. Morphogenetic effects were studied with regard to cell divisions and GA₃-induced antheridiogenesis. As compared with both the GA⁻₃ and GA⁺₃ control samples, the extract-treated prothallia exhibited considerably lowered number of cells and altered morphology. Antheridial differentiation in prothallia of A. phyllitidis was severely inhibited when peptidic extract was added to medium containing GA₃. Considering endocytotic uptake, evidenced in root meristems, and those effects which have been observed in plant and human cells, the activity of extracts obtained from male sex organs of Chara may be interpreted as inhibitory influence acting via repression or modification of the genetic device of the cells rather, than a direct consequence of the retardation of cell division cycles.
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