Abstract
Perilla frutescens var. crispa, a short-day plant, continues to flower under long-day if once photoinduced. This reminds us of vernalization where the low temperature effect is maintained for a long period of time. Such an analogy suggests the common mechanism functioning in both phenomena. Vernalization is regulated by the gene expression through DNA methylation and demthylation. Accordingly, seeds of green and red P. frutescens were treated with 250μM 5-azacytidine. The treatment induced flowering under long-day condition in both varieties. This is the first evidence indicating flower-induction by DNA-demethylating reagent in plant of which flowering is photperiodically regulated. Anything other than flowering was not influenced by 5-azacytidine although the vegetative growth was suppressed a little. 5-Azacytidine applied to shoot apex is also effective, and this treatment induced flower buds at the lower nodes, suggesting that 5-azacytidine induced the production of transmissible flower-inducing substance(s).
