Two novel NAC transcription factors regulate gene expression and flowering time by associating with the histone demethylase JMJ14

The histone demethylase JMJ14 catalyzes histone demethylation at lysine 4 of histone 3 and is involved in transcriptional repression and flowering time control in Arabidopsis. Here, we report that JMJ14 is physically associated with two previously uncharacterized NAC transcription factors, NACO50 and NACO52. The NACO50/052-RNAi plants and the CRISPR-CAS9-mediated nac050/ 052 double mutant plants show an early flowering phenotype, which is similar to the phenotype of jmj14, suggesting a functional association between JMJ14 and NACO50/052. RNA-seq data indicated that hundreds of common target genes are co-regulated by JMJ14 and NAC50/052. Our ChIP analysis demonstrated that JMJ14 and NACO50 directly bind to co-upregulated genes shared in jmj14 and NACO50/ 052RNAi, thereby facilitating H3K4 demethylation and transcriptional repression. The NACO50/052 recognition DNA cis-element was identified by an electrophoretic mobility shift assay at the promoters of its target genes. Together, our study identifies two novel NAC transcription repressors and demonstrates that they are involved in transcriptional repression and flowering time control by associating with the histone demethylase JMJ14.