Flowering induced by 5‐azacytidine, a DNA demethylating reagent in a short‐day plant, <i>Perilla frutescens</i> var. <i>crispa</i>

Abstract

Treatment with 5‐azacytidine, a DNA demethylating reagent, induced flowering in Perilla frutescens (L.) Britton var. crispa (Thunb. ex Murray) Decne. ex L. H. Bailey, an absolute short‐day plant under long days. The 5‐azacytidine treatment induced slight suppression of vegetative growth but had no obvious effect on any other phenotypes. The Southern hybridization analysis of the genomic DNA isolated from the leaves of 5‐azacytidine‐treated plants and digested with restriction enzyme, methylation‐insensitive Msp I or methylation‐sensitive Hpa II with P. frutescens 25S‐18S rDNA intergenic spacer probe indicated that the 5‐azacytidine treatment caused demethylation of the genomic DNA. The 5‐azacytidine‐induced flowering was delayed as compared with the short day‐induced flowering. Flowers were formed even at the lower nodes which had not been directly treated with 5‐azacytidine. The results suggest that DNA demethylation induced flowering by inducing the production of a transmissible flowering stimulus in P. frutescens .