Histone Demethylases JMJ30 and JMJ32 Modulate the Speed of Vernalization Through the Activation of in .

Vernalization is the promotion of flowering after prolonged exposure to cold. In , vernalization induces epigenetic silencing of the floral repressor gene (). Among the repressive epigenetic marks, the trimethylation of lysine 27 on histone H3 proteins (H3K27me3) is a critical contributor to the epigenetic silencing of . The deposition of H3K27me3 is mediated by Polycomb Repressive Complex 2 (PRC2). Conversely, the elimination of H3K27me3 is mediated by histone demethylases, Jumonji-C domain-containing protein JMJ30 and its homolog JMJ32. However, the role of JMJ30 and JMJ32 in vernalization is largely unknown. In this study, we found that cold treatment dramatically reduced the expression levels of and did not reduce those of JMJ32. Next, by using the genetic approach, we found that the flowering of was accelerated under moderate vernalized conditions. Under moderate vernalized conditions, the silencing of occurred more quickly in than in the wild type. These results suggested that the histone demethylases JMJ30 and JMJ32 brake vernalization through the activation of . Our study suggested that PRC2 and Jumonji histone demethylases act in an opposing manner to regulate flowering time via epigenetic modifications.