The influence of the disappearance of plasmodesmal connections between antheridia and thallus on 3H-GA3 transport.

Autoradiograms of antheridial filaments labelled after tritiated gibberellic acid (3H-GA3) administration at various developmental stages of Chara contraria (in control and after plasmolysis) show that intensity of gibberellin binding depends mainly on symplasmic connection of antheridia with thallus. Young antheridia before spontaneous symplasmic isolation which precedes spermiogenesis, contain antheridial filaments labelled more intensively than the older ones. This difference disappears if antheridia were plasmolyzed and symplasmic isolation was induced before incubation. These findings are in agreement with the previous results obtained in Chara vulgaris after 14C-GA3 treatment.