AUTHOR=Maruoka Takashi , Gan Eng-Seng , Otsuka Nana , Shirakawa Makoto , Ito Toshiro 

TITLE=Histone Demethylases JMJ30 and JMJ32 Modulate the Speed of Vernalization Through the Activation of FLOWERING LOCUS C in Arabidopsis thaliana

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.837831

DOI=10.3389/fpls.2022.837831

ISSN=1664-462X

ABSTRACT=<p>Vernalization is the promotion of flowering after prolonged exposure to cold. In <italic>Arabidopsis thaliana</italic>, vernalization induces epigenetic silencing of the floral repressor gene <italic>FLOWERING LOCUS C</italic> (<italic>FLC</italic>). Among the repressive epigenetic marks, the trimethylation of lysine 27 on histone H3 proteins (H3K27me3) is a critical contributor to the epigenetic silencing of <italic>FLC</italic>. 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 <italic>JMJ30</italic> and did not reduce those of JMJ32. Next, by using the genetic approach, we found that the flowering of <italic>jmj30 jmj32</italic> was accelerated under moderate vernalized conditions. Under moderate vernalized conditions, the silencing of <italic>FLC</italic> occurred more quickly in <italic>jmj30 jmj32</italic> than in the wild type. These results suggested that the histone demethylases JMJ30 and JMJ32 brake vernalization through the activation of <italic>FLC</italic>. Our study suggested that PRC2 and Jumonji histone demethylases act in an opposing manner to regulate flowering time via epigenetic modifications.</p>