The Arabidopsis Mediator Subunit MED25 Differentially Regulates Jasmonate and Abscisic Acid Signaling through Interacting with the MYC2 and ABI5 Transcription Factors

• Published in: The Plant cell 2012-07, Vol.24 (7), p.2898-2916
• Main Authors: Chen, Rong, Jiang, Hongling, Li, Lin, Zhai, Qingzhe, Qi, Linlin, Zhou, Wenkun, Liu, Xiaoqiang, Li, Hongmei, Zheng, Wenguang, Sun, Jiaqiang, Li, Chuanyou
• Format: Article
• Language: English
• Subjects: abscisic acid; Abscisic Acid - metabolism; Antibodies; Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors - genetics; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors - metabolism; Basic-Leucine Zipper Transcription Factors - genetics; Basic-Leucine Zipper Transcription Factors - metabolism; Cyclopentanes - metabolism; Flowers - cytology; Flowers - genetics; Flowers - physiology; gene expression; Gene expression regulation; Gene Expression Regulation, Plant - physiology; Genes; Germination; jasmonic acid; Mutation; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Oxylipins - metabolism; Plant cells; Plant Growth Regulators - metabolism; Plant Leaves - cytology; Plant Leaves - genetics; Plant Leaves - physiology; Plant Roots - cytology; Plant Roots - genetics; Plant Roots - physiology; Plants; Plants, Genetically Modified; Promoter Regions, Genetic; Protein Interaction Mapping; Protein Structure, Tertiary; Proteins; Seedlings; Seedlings - cytology; Seedlings - genetics; Seedlings - physiology; Seeds - cytology; Seeds - genetics; Seeds - physiology; Signal Transduction - physiology; Time Factors; Transcription factors; Transcriptional regulatory elements; Yeasts
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.112.098277

Transcriptional regulation plays a central role in plant hormone signaling. At the core of transcriptional regulation is the Mediator, an evolutionarily conserved, multisubunit complex that serves as a bridge between gene-specific transcription factors and the RNA polymerase machinery to regulate transcription. Here, we report the action mechanisms of the MEDIATOR25 (MED25) subunit of the Arabidopsis thaliana Mediator in regulating jasmonate- and abscisic acid triggered gene transcription. We show that during jasmonate signaling, MED25 physically associates with the basic helix-loophelix transcription factor MYC2 in promoter regions of MYC2 target genes and exerts a positive effect on MYC2-regulated gene transcription. We also show that MED25 physically associates with the basic Leu zipper transcription factor ABA-INSENSITIVE5 (ABI5) in promoter regions of ABI5 target genes and shows a negative effect on ABI5-regulated gene transcription. Our results reveal that underlying the distinct effects of MED25 on jasmonate and ABA signaling, the interaction mechanisms of MED25 with MYC2 and ABI5 are different. These results highlight that the MED25 subunit of the Arabidopsis Mediator regulates a wide range of signaling pathways through selectively interacting with specific transcription factors.