Arabidopsis Topless‐related 1 mitigates physiological damage and growth penalties of induced immunity

Abstract

Summary Transcriptional corepressors of the Topless (TPL) family regulate plant hormone and immunity signaling. The lack of a genome‐wide profile of their chromatin associations limits understanding of the TPL family roles in transcriptional regulation. Chromatin immunoprecipitation with sequencing (ChIP‐Seq) was performed on Arabidopsis thaliana lines expressing GFP‐tagged Topless‐related 1 (TPR1‐GFP) with and without constitutive immunity via Enhanced Disease Susceptibility 1 (EDS1). RNA‐Seq profiling of the TPR1‐GFP lines and pathogen‐infected tpl/tpr mutants, combined with measuring immunity, growth, and physiological parameters was employed to investigate TPL/TPR roles in immunity and defense homeostasis. TPR1 was enriched at promoter regions of c. 1400 genes and c. 10% of the detected binding required EDS1 immunity signaling. In a tpr1 tpl tpr4 (t3) mutant, resistance to bacteria was slightly compromised, and defense‐related transcriptional reprogramming was weakly reduced or enhanced, respectively, at early (< 1 h) and late 24 h stages of bacterial infection. The t3 plants challenged with bacteria or pathogen‐associated molecular pattern nlp24 displayed photosystem II dysfunctions. Also, t3 plants were hypersensitive to phytocytokine pep1 at the level of root growth inhibition. Transgenic expression of TPR1 rescued these t3 physiological defects. We propose that TPR1 and TPL family proteins function in Arabidopsis to reduce detrimental effects associated with activated transcriptional immunity.

An epigenetic timer regulates the transition from cell division to cell expansion during Arabidopsis petal organogenesis

“…The enrichment of TPL on TCP5 promoter regions was detected using and anti-HA antibody with significant enrichment observed in the presence of RBE, at the TCP5 promoter regions W1, W2, W3 and P1 (Fig 4A and 4B). Consistent with this, the TPL homologue-TPR1 acts as a transcriptional corepressor and preferentially binds to regions around 1kb upstream of the TSS [30]. We also carried out ChIP assays using a 35S::Myc-HDA19 transgene.…”

Identification of a major QTL and candidate genes analysis for branch angle in rapeseed (Brassica napus L.) using QTL-seq and RNA-seq

“…ADS3/FAD5 encodes plastidic palmitoyl-monogalactosyldiacylglycerol D7 desaturase, which is responsible for the synthesis of 16:1 fatty acid from galactolipids and sulfolipids ( Smith et al., 2013 ). WSIP2 is involved in physiological damage and plant immunity ( Griebel et al., 2023 ). It is thus clear that the regulation of the formation of branching angles in rapeseed is complicated.…”

Wheat Transcriptional Corepressor TaTPR1 Suppresses Susceptibility Genes TaDND1/2 and Potentiates Post-Penetration Resistance against Blumeria graminis forma specialis tritici

“…tritici. Similarly, knocking out AtTPR1 and its close homologs in Arabidopsis or the silencing of NbTPR1 in N. benthamiana compromised the plant ETI and PTI [24][25][26]. It was recently demonstrated that the Arabidopsis TPR1 protein could reduce the detrimental effects associated with an activated transcriptional immunity [14].…”

“…There is increasing evidence showing that TPR1 plays a vital role in the regulation of plant immunity [24]. Indeed, knocking out Arabidopsis AtTPR1 and its close homologs compromises the immunity mediated by the toll-like/interleukin-1 receptor (TIR)-NB-LRR R protein, a suppressor of npr1-1, constitutive 1 (AtSNC1), whereas the overexpression of AtTPR1 constitutively activates AtSNC1-mediated immune responses [25,26]. Similarly, the silencing of NbTPR1 in Nicotiana benthamiana compromised the flg22-triggered PTI defense response [27].…”