DOI: 10.1073/pnas.2532739123 ISSN: 0027-8424
Brassinosteroid-regulated transcription factors confer epigenetic changes that repress plant immunity
Veronica E. Ramirez, Haiwei Shuai, Fang-Yu Hwu, Rashmi R. Hazarika, Chia-Nan Tao, Sera Choi, Robert S. Piecyk, Susanne I. Wudy, Michael Gigl, Johannes W. Bagnoli, Sarah Brajkovic, Pablo Albertos, Yuanyuan Liang, Andreas Keymer, Corinna Dawid, Wolfgang Enard, A. Corina Vlot, Caroline Gutjahr, Martin Parniske, Bernhard Kuster, Tobias Sieberer, Christina Ludwig, Cyril Zipfel, Jurriaan Ton, Frank Johannes, Brigitte Poppenberger
When organisms encounter pathogens, they rapidly activate complex defense programs to ensure survival. While these immune responses are vital, they often also incur trade-offs, such as reduced growth and development and must therefore be tightly controlled. In this study, we reveal that the steroid hormones brassinosteroids (BRs) contribute to this control in
Arabidopsis thaliana
by repressing immunity-related genes. We provide evidence that the BR-regulated basic helix–loop–helix (bHLH) transcription factor CESTA (CES), along with its homologs BR ENHANCED EXPRESSION (BEE)1-3, mediate DNA methylation changes at transposable element (TE)-rich loci containing nucleotide-binding leucine-rich-repeat (NLR)-type receptor genes, including
SUPPRESSOR OF NPR1-1 CONSTITUTIVE 1
(
SNC1
). These CES-induced methylation changes correlate with altered splicing of
SNC1
pre-mRNA, a process that requires the BR receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1). In support, we show that CES associates with components of the chromatin remodeling and splicing machinery. Together, our findings reveal a previously unrecognized BR-induced mechanism that modulates the epigenetic and post transcriptional regulation of immune genes, enabling plants to prioritize growth over defense.