The histone variant H3.14 is an early player in the abiotic stress response of Arabidopsis.

The combinatorial changes in DNA methylation, post-translational histone modifications, and histone variants underlie the complexity of chromatin structure and function. In the case of histone H3, apart from the canonical H3.1 and the variant H3.3, highly conserved in eukaryotes, there are additional members associated with unique developmental features, some of which have an unknown function. Here, we have investigated one of these, H3.14, a novel Arabidopsis H3 variant rapidly and transiently induced upon abiotic stress in a subset of responsive cells located in the root transition zone. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) data showed that H3.14 exhibits differential binding patterns in repressed genes involved in cell growth and in activated genes involved in the stress response. This dual role, further supported by genetic and cell biology data, led us to conclude that H3.14 is specifically tailored for the transcriptional rewiring during the early abiotic stress response.