Abstract
We previously indicated that epigenetical regulation is involved in the photoperiodic flowering in Perilla frutescens var. crispa whose flowering state lasts long as the low temperature effect lasts long in vernalization. Accordingly, we investigated a possible correlation between the character of permanent flowering state and the ability to flower by DNA demethylation.
Four plant species were photoperiodicaly induced to flower and then transferred to under non-inductive condition. Pharbitis nil and Lemna paucicostata reverted to vegetative growth, whereas Silene armeria and Xanthium strumarium did not. Treatment with 5-azacytidine caused flowering in S. armeria, but not in X. strumarium. The results suggest that the permanent flowering state is not necessarily correlated with the flower-induction by DNA demethylation. The mechanism of flowering in X. strumarium may differ from that in P. furutescens and S. armeria. This paradox will be discussed by analyzing the level of DNA methylation in rDNA intergenic spacer region.
