Studies on the role of gibberellins in the regulation of spermatogenesis in Chara vulgaris L.

Abstract

Antheridia from isolated nodes of Chara vulgaris, developing in the presence of either AMO-1618 or GA3, were studied. AMO-1618 which lowers the level of endogenous gibberellins causes a significant, proportional to the concentration, reduction in: 1) the number of antheridial filaments formed in antheridia, 2) spermatid number within a filament, as a result of eliminating one mitotic division at the first stage of spermatogenesis. Exogenous GA3 at the concentration 10-5 M evokes opposite effect i.e. increase in the number of antheridial filaments and increase in the number of spermatids within filament. Total number of spermatids within an antheridium decreases under the influence of 10-4M AMO-1618 three times in comparison with the control, whereas it increases twice following 10-5M GA3 treatment. It has been suggested that the normal course of spermatogenesis requires precisely determined level of endogenous gibberellins.

Keywords

• spermatogenesis
• GA3
• AMO-1618
• Chara vulgaris L.