HISTONE DEACETYLASE 9 stimulates auxin-dependent thermomorphogenesis in Arabidopsis thaliana by mediating H2A.Z depletion.
Lennard C van der WoudeGiorgio PerrellaBasten L SnoekMark van HoogdalemOndřej NovákMarcel C van VerkHeleen N van KootenLennert E ZornRolf TonckensJoram A DongusMyrthe PraatEvelien A StoutenMarcel C G ProveniersElisa VellutiniEirini PatitakiUmidjon ShapulatovWouter KohlenSureshkumar BalasubramanianKaren LjungAlexander R van der KrolSjef SmeekensEirini KaiserliMartijn van ZantenPublished in: Proceedings of the National Academy of Sciences of the United States of America (2019)
Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the YUCCA8 locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with YUCCA8, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis.