Ethylene is a modulator of gibberellic acid-induced antheridiogenesis in Anemia phyllitidis gametophytes

Abstract

In fern (Anemia phyllitidis) gametophytes cellulose in the walls of the antheridial zone cells which was organized in clusters and spots was transformed via dispersed form to fibrillar arrangement (layered in oblique and perpendicular array in relation to the transverse direction of cell expansion) during antheridiogenesis induced by gibberellic acid (GA3) and/or enhanced by 1-aminocyclopropane-1-carboxylic acid (ACC). In the ACC-treated gametophytes, where antheridia were not induced, the cellulose was arranged in the same manner. Aminooxyacetic acid (AOA), which inhibits antheridiogenesis and development of fern gametophytes, produced in the cell walls both random and longitudinal type of organization of cellulose microfibrils, however, in the GA3/AOA-treated plants the oblique type was also observed. The total numbers of cells with perpendicular and/or oblique type of cellulose microfibrils in the GA3-, GA3/ACC-and GA3/AOA-treated gametophytes corresponded to the average number of antheridia formed. Moreover, it was found that the extracts from the gametophytes treated with GA3 or with the mixture of GA3 and ACC contained significantly less soluble sugars but more α-amylase-and endoglucanase-released sugars than the extracts from the gametophytes of the other series. Thin layer chromatography of the samples from the cell wall extracts hydrolyzed by endoglucanase contained xylose and cellobiose which suggested that these sugars built the xyloglucans, hemicellulose polymers responsible for tethering of walls of fern gametophyte cells like in higher plants.