DNA demethylase ROS1 negatively regulates the imprinting of <i>DOGL4</i> and seed dormancy in <i>Arabidopsis thaliana</i>

Significance Genomic imprinting is a form of epigenetic regulation causing parent-of-origin differential expression of maternally or paternally inherited alleles. The DNA demethylase DME regulates the imprinting of many genes in the Arabidopsis endosperm. It is not known whether and how other DNA demethylases may also regulate imprinting. Here, we discovered that the DNA demethylase ROS1 negatively regulates DOGL4 imprinting via demethylation of the DOGL4 promoter on the paternal allele. Additionally, we found that DOGL4 negatively regulates seed dormancy and abscisic acid (ABA) response and that ROS1 regulates seed dormancy and ABA response by controlling DOGL4 expression. Our results thus suggest a different mechanism of regulation of gene imprinting and reveal important roles of ROS1 in the regulation of seed dormancy and ABA response.