OTU5 tunes environmental responses by sustaining chromatin structure

ABSTRACTPhenotypic plasticity is dependent on the correct interpretation of environmental cues. We recently showed that the deubiquitinase OTU5 is required for orchestrating internal and external signals, tuning the morphogenesis of epidermal cells to the prevailing conditions. Homozygous otu5 mutants developed long and dense root hairs, resembling phosphate-deficient plants. The phenotype of otu5 plants was similar to that of arp6 plants, which carries a mutation that compromises the deposition of H2A.Z. Homozygous otu5 arp6 double mutants exhibited a synergistic phenotype, suggesting that the two mutations are functionally related. In a multi-omics approach comprising genome-wide DNA methylation, detection of various post-translational histone modifications as well as transcriptomic and proteomic surveys, we found that OTU5 is critical for maintaining the abundance of stimulus-responsive proteins, probably by modulating chromatin structure. It is concluded that changes in protein abundance and phenotypi...