Salt stress activates CDK8-AHL10-SUVH2/9 module to dynamically regulate salt tolerance in Arabidopsis

ABSTRACT: Salt stress leads to devastating effects to agriculture. Presently, the key regulators that control transcriptional dynamics of salt-responsive genes remain poorly understood in plants. Here, we revealed that salt stress can substantially induce the kinase activity of Mediator subunit cyclin-dependent kinase 8 (CDK8), which is essential for its positive role in regulating salt tolerance. We subsequently uncovered that CDK8 phosphorylates the AT-hook motif nuclear-localized protein 10 (AHL10) at serine 314 through direct interaction, thereby promoting its protein degradation under salt stress. In addition, we created ahl10 mutants by CRISPR-Cas9 and showed the negative role of AHL10 in salt tolerance. Moreover, transcriptome analysis revealed that CDK8 regulates more than 20% of salt-responsive genes, about half of which are co-regulated by AHL10. Chromatin immunoprecipitation sequencing (ChIP-seq) further demonstrated that AHL10 binds to the AT-rich DNA sequence related to the nuclear matrix-attachment regions (MARs) in the salt-responsive gene promoters to repress their transcription. Importantly, we further found that AHL10 physically interacts with SU(VAR)3-9 homologs SUVH2/9, thereby repressing transcription of salt-responsive genes in a H3K9me2-dependent epigenetic regulatory manner. Overall, our study identified the CDK8-AHL10-SUVH2/9 module as a key molecular switch controlling plant transcriptional dynamics in response to salt stress.

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

SUBMITTER: YingFang Zhu 

PROVIDER: PXD057837 | JPOST Repository | Sun Feb 02 00:00:00 GMT 2025

REPOSITORIES: jPOST