Journal Article

GROWTH-REGULATING FACTORS Interact with DELLAs and Regulate Growth in Cold Stress

Alkofer, Angela, Lantzouni, Ourania, Schwechheimer, Claus, Falter-Braun, Pascal

2020

Overview

DELLA proteins are repressors of the gibberellin (GA) hormone signaling pathway that act mainly by regulating transcription factor activities in plants. GAs induce DELLA repressor protein degradation and thereby control a number of critical developmental processes as well as responses to stresses such as cold. The strong effect of cold temperatures on many physiological processes has rendered it difficult to assess, based on phenotypic criteria, the role of GA and DELLAs in plant growth during cold stress. Here, we uncover substantial differences in the GA transcriptomes between plants grown at ambient temperature (21°C) and plants exposed to cold stress (4°C) in Arabidopsis (Arabidopsis thaliana). We further identify over 250, to the largest extent previously unknown, DELLA-transcription factor interactions using the yeast two-hybrid system. By integrating both data sets, we reveal that most members of the nine-member GRF (GROWTH REGULATORY FACTOR) transcription factor family are DELLA interactors and, at the same time, that several GRF genes are targets of DELLA-modulated transcription after exposure to cold stress. We find that plants with altered GRF dosage are differentially sensitive to the manipulation of GA and hence DELLA levels, also after cold stress, and identify a subset of cold stressresponsive genes that qualify as targets of this DELLA-GRF regulatory module.

• Publisher: American Society of Plant Biologists (ASPB),American Society of Plant Biologists
• Subject: Arabidopsis - cytology / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Cell Count / Cell Size / Cold-Shock Response - drug effects / Cold-Shock Response - genetics / Gene Expression Regulation, Plant - drug effects / Gibberellins - metabolism / Gibberellins - pharmacology / MicroRNAs - genetics / MicroRNAs - metabolism / Plant Leaves - drug effects / Plant Leaves - genetics / Plant Leaves - growth & development / Plant Roots - drug effects / Plant Roots - growth & development / Plants, Genetically Modified / Protein Binding - drug effects / Signal Transduction / Transcription Factors - metabolism / Transcriptome - drug effects / Transcriptome - genetics / Triazoles - pharmacology