Journal Article

RDM4 modulates cold stress resistance in Arabidopsis partially through the CBF‐mediated pathway

Gong, Yuehua, Hu, Yuanlei, Mu, Zixin, Zhu, Jian‐Kang, Wang, Yanping, Chan, Zhulong, He, Xin‐Jian, Wang, Haiqing, Cao, Minjie, Deng, Xin

2016

Overview

The C‐REPEAT‐BINDING FACTOR (CBF) pathway has important roles in plant responses to cold stress. How the CBF genes themselves are activated after cold acclimation remains poorly understood. In this study, we characterized cold tolerance of null mutant of RNA‐DIRECTED DNA METHYLATION 4 (RDM4), which encodes a protein that associates with RNA polymerases Pol V and Pol II, and is required for RNA‐directed DNA methylation (RdDM) in Arabidopsis. The results showed that dysfunction of RDM4 reduced cold tolerance, as evidenced by decreased survival and increased electrolyte leakage. Mutation of RDM4 resulted in extensive transcriptomic reprogramming. CBFs and CBF regulon genes were down‐regulated in rdm4 but not nrpe1 (the largest subunit of PolV) mutants, suggesting that the role of RDM4 in cold stress responses is independent of the RdDM pathway. Overexpression of RDM4 constitutively increased the expression of CBFs and regulon genes and decreased cold‐induced membrane injury. A great proportion of genes affected by rdm4 overlapped with those affected by CBFs. Chromatin immunoprecipitation results suggested that RDM4 is important for Pol II occupancy at the promoters of CBF2 and CBF3. We present evidence of a considerable role for RDM4 in regulating gene expression at low temperature, including the CBF pathway in Arabidopsis.

• Publisher: Academic Press,New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: acclimation / Acclimatization / Arabidopsis / Arabidopsis - genetics / Arabidopsis - physiology / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Cell Membrane - metabolism / chromatin / cold / cold stress / Cold Temperature / Cold tolerance / C‐REPEAT‐BINDING FACTOR (CBF) / Deoxyribonucleic acid / DNA / DNA methylation / Electrolyte leakage / electrolytes / Electrolytes - metabolism / Freezing / Gene Expression Profiling / gene expression regulation / Gene Expression Regulation, Plant / Gene Ontology / gene overexpression / Genes, Plant / Low temperature / mutants / mutation / Mutation - genetics / Oxidative Stress - genetics / Plant Leaves - physiology / plant response / Pol II / precipitin tests / Promoter Regions, Genetic - genetics / Protein Binding / Reactive Oxygen Species - metabolism / regulon / RNA / RNA Polymerase II - metabolism / RNA‐directed DNA methylation / RNA‐DIRECTED DNA METHYLATION 4 (RDM4) / Seedlings - metabolism / stress response / stress tolerance / Stress, Physiological - genetics / temperature / Trans-Activators - genetics / Trans-Activators - metabolism / Transcription Factors - genetics / Transcription Factors - metabolism / transcriptome / transcriptomics