Vernalization articles from across Nature Portfolio

In this study, De Niu et al. report a two-step molecular mechanism, embryonic resetting of cold-induced TaVRN1 activation and subsequent TaVRN2 reactivation by light during seed germination, to re-establish vernalization requirements in wheat.

The study shows that the cold-induced Polycomb-repressed chromatin state at FLOWERING LOCUS C is meiotically stable in female but not male gametogenesis. This epigenetic cold memory is maternally inherited to the zytote and early embryos.

Plants use multiple cues to monitor seasonal temperatures. Here, the authors show that Arabidopsis requires not only prolonged cold, but the absence of temperature spikes above 15 °C to epigenetically silence FLC during winter.

VRN1 is a central regulator of flowering following prolonged cold exposure in cereals. Here Deng et al. combine ChIP-seq and RNA-seq to identify downstream targets of VRN1 in barley and demonstrate direct links between the flowering pathway and genes controlling other important agronomic traits.

In temperate cereals such as winter wheat, prolonged periods of cold induce upregulation of TaVRN1 to control the timing of seasonal flowering. Xiao et al. show TaVRN1 mRNA accumulation is regulated by O-GlcNAc modification of the RNA-binding protein TaGRP2, which increases progressively in response to cold.

Biennial plants require exposure to the cold of winter to overcome a block to flowering in the spring. The molecular role of FRIGIDA, a key component of the system that establishes the cold requirement in Arabidopsis, is to assemble a protein super-complex that promotes expression of a flowering repressor in the autumn.