ERFVII ‐controlled hypoxia responses are in part facilitated by MEDIATOR SUBUNIT 25 in Arabidopsis thaliana

作者：Jos H. M. Schippers, Kira von Bongartz, Lisa Laritzki, Stephanie Frohn, Stephanie Frings, Tilo Renziehausen, Frauke Augstein, Katharina Winkels, Katrien Sprangers, Rashmi Sasidharan, Didier Vertommen, Frank Van Breusegem, Sjon Hartman, Gerrit T.S. Beemster, Amna Mhamdi, Joost T. van Dongen, Romy Schmidt · 发表于：The Plant Journal · 年份：2024 · DOI：10.1111/tpj.17018 · 被引用次数：23 · 研究领域：Plant responses to water stress、Lipid metabolism and biosynthesis、Coastal wetland ecosystem dynamics

Flooding impairs plant growth through oxygen deprivation, which activates plant survival and acclimation responses. Transcriptional responses to low oxygen are generally associated with the activation of group VII ETHYLENE-RESPONSE FACTOR (ERFVII) transcription factors. However, the exact mechanisms and molecular components by which ERFVII factors initiate gene expression are not fully elucidated. Here, we show that the ERFVII factors RELATED TO APETALA 2.2 (RAP2.2) and RAP2.12 cooperate with the Mediator complex subunit AtMED25 to coordinate gene expression under hypoxia in Arabidopsis thaliana. Respective med25 knock-out mutants display reduced low-oxygen stress tolerance. AtMED25 physically associates with a distinct set of hypoxia core genes and its loss partially impairs transcription under hypoxia due to decreased RNA polymerase II recruitment. Association of AtMED25 with target genes requires the presence of ERFVII transcription factors. Next to ERFVII protein stabilisation, also the composition of the Mediator complex including AtMED25 is potentially affected by hypoxia stress as shown by protein-complex pulldown assays. The dynamic response of the Mediator complex to hypoxia is furthermore supported by the fact that two subunits, AtMED8 and AtMED16, are not involved in the establishment of hypoxia tolerance, whilst both act in coordination with AtMED25 under other environmental conditions. We furthermore show that AtMED25 function under hypoxia is independent of ethy...