Gibberellic acid and ethylene control male sex determination and development of anemia phyllitidis gametophytes

Abstract

Development and male sex determination in homosporous fern -gametophytes is controlled by antheridiogens, gibberellin derivatives, which are secreted by hermaphrodites or female and promote the development of males from sexually undetermined gametophytes. In Anemia phyllitidis, antheridiogenesis is a complex process and can be prematurely induced by gibberellic acid (GA3) which imitates the action of antheridic acid, the main antheridiogen of that fern. GA3 in young gametophytes induces many specific cytomorphological and metabolical features during induction and expression phases of male sex determination which allowed to describe the useful three-zonal model. Influence of GA3 on dispersion of nuclear chromatin, induction of cell division cycle, sugar metabolism, and cell wall structural reorganization leads to transverse cell growth and asymmetrical division of antheridial mother cells and to antheridia formation. These processes are modulated by ethylene playing the role of a secondary messenger. Disorganization of communication between cells in gametophytes can cause death of individual cells as well as whole gametophytes.