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This work shows that two H3K4me2/me3 readers recruit PRC2 to timely represses FT expression following daily rhythmic FT activation under inductive long days, which prevents excessive FT expression to precisely control flowering time in Arabidopsis.

Pesticide resistance poses a serious threat to global food security. In this study, the authors show the mode of action of various diamide insecticides and elucidate the molecular mechanisms underlying resistance mutations.

This study reported the structures of plant DNA demethylase ROS1 in complexes with substrate DNA, which revealed insights into the molecular basis of the plant-specific ROS1-mediated DNA demethylation.

High levels of superoxide (O₂•^–) are known to regulate plant stem cell behavior, but its downstream effectors remain unclear. O₂•^– was found to directly promote DNA demethylase ROS1 activity to maintain the stemness of plant shoot apical meristem.

DNA methylation and H3K9 dimethylation are two linked epigenetic marks of silenced chromatin in plants that depend on the activity of CMT3/2 and SUVH4/5/6. Here the authors identify AGDP1 as an H3K9me2-binding protein required for heterochromatic non-CG DNA methylation, H3K9 dimethylation, and transcriptional silencing.

PIWI protein contains arginine rich motifs that are post-translationally modified to symmetrically methylated arginine (sDMA) residues. Here the authors show that piRNA loading into Aub triggers sDMA modification which is recognized by Krimper to promote formation of Krimper-Aub-Ago3 complex for piRNA amplification in Drosophila.

In plants, RNA-directed DNA methylation (RdDM) is a de novo DNA methylation pathway that is responsible for transcriptional silencing of repetitive elements. Here, the authors characterized a new RdDM factor, RDM15, and show that it is required for RdDM-dependent DNA methylation and siRNA accumulation at a subset of RdDM target loci.

Two B3 domain transcription factors are important for the resetting of the vernalized state in the embryos of Arabidopsis by competing against repressive Polycomb partners and recruiting the scaffold protein FRIGIDA to establish an activate chromatin state at FLC.

Jumonji domain-containing histone demethylases regulate flowering in plants. Here Zheng et al. show that Arabidopsis JMJ13 is an H3K27me3 demethylase that recognizes H3K27me3 via hydrogen bonding and hydrophobic interactions and affects both photoperiod and temperature-dependent flowering responses.

Histone 3 Lys 27 trimethylation (H3K27me3) mediates epigenetic silencing of gene expression. Here, Zhang et al. show that in Arabidopsis, the BAH-domain H3K27me3-reader protein AIPP3 forms a complex with PHD proteins and CPL2, a plant-specific Pol II phosphatase, to inhibit Pol II activity by dephosphorylation.

DNA methylation and H3K9 methylation are typically associated with gene silencing. Genetic, genomic, structural and biochemical data reveal functional connections between these two epigenetic marks. They also highlight how specialized protein domains that recognize the marks are essential for their establishment and maintenance at appropriate genomic loci.

Histone mark reader proteins bind to particular histone modifications and regulate chromatin state. Here, Qian et al. show that the SHORT LIFE reader has a unique ability to recognize both activating and repressive histone marks and that these interactions enable SHORT LIFE to repress flowering in plants.

Yuehui He and colleagues show that VAL1 and VAL2 bind to a cis-regulatory element at the FLC locus and are required for its epigenetic silencing during vernalization in Arabidopsis. They further report that VAL proteins recognize the repressive histone mark H3K27me3 and are necessary for genomic binding of the Polycomb silencing partner LHP1.

Non-CG methylation is abundant in plants, but its functions are poorly understood. A new study has uncovered the contributions of each non-CG methyltransferase, including the poorly characterized methyltransferase CMT2, to DNA methylation patterning and gene silencing. The results suggest that non-CG methyltransferases participate in self-reinforcing loop mechanisms with histone H3 K9 methylation and small RNAs to control gene silencing throughout the Arabidopsis genome.

Structural and biochemical studies of the bacterial NAD-decapping enzyme, NudC, in complex with NAD or its cleavage product NMN reveal the critical residues for substrate recognition and the preference of NudC for NAD-capped RNA.

In Arabidopsis, the RNA-directed DNA methylation pathway is important for establishing and maintaining DNA methylation — here Pol V is shown to depend on SUVH2 and SUVH9, where both of these proteins are proposed to bind specifically to methylated DNA to recruit Pol V, providing a self-reinforcing loop mechanism for maintenance of RNA-directed DNA methylation.

In Arabidopsis, RNA-directed DNA methylation is a poorly understood gene silencing pathway in which small interfering RNAs generated by RNA polymerase IV (Pol-IV) target a DNA methyltransferase to its sites of action; here structural and genomic analyses demonstrate that SHH binds chromatin via repressive histone modifications and recruits Pol-IV to enable siRNA production.

Plants respond to abiotic stress via the phytohormone ABA. Here, Cao et al. report a series of new ABA receptor agonists, named AMFs, which have higher receptor-binding affinities and show that, when employed in tandem with ABA receptor overexpression, can significantly increase drought resistance

A fungal ten-eleven translocation (TET) dioxygenase homolog, CcTet, is found to have both 5-methylcytosine (5mC) and N⁶-methyladenine (6mA) demethylase activity. Structure-based engineering of CcTet yielded a 6mA-specific demethylase, offering a useful tool for the manipulation and functional study of 6mA.

EBS, which prevents premature flowering in Arabidopsis, is shown to bind H3K27me3 and H3K4me3 via different domains. Disruption of either EBS–H3K27me3 or EBS–H3K4me3 interaction induces early floral transition.

Cryogenic electron microscopy structures of DDM1–nucleosome complexes in ADP–BeF_x-bound, ADP-bound and nucleotide-free conformations reveal insights into the mechanism underlying chromatin remodelling by DDM1, a key chromatin remodeller involved in plant DNA methylation.