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bioRxiv · 10.1101/2021.07.07.451397

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

Griebel, T.·Lapin, D.·Locci, F.·Kracher, B.·Bautor, J.·Qiu, J.·Concia, L.·Benhamed, M.·Parker, J. E.
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Abstract

Transcriptional corepressors of the Topless family are important regulators of plant hormone and immunity signaling. The lack of a genome-wide profile of their chromatin associations limits understanding of transcriptional regulation in plant immune responses. Chromatin immunoprecipitation with sequencing (ChIP-seq) was performed on GFP-tagged Topless-related 1 (TPR1) expressed in Arabidopsis thaliana lines with and without constitutive immunity dependent on Enhanced Disease Susceptibility 1 (EDS1). RNA-seq profiling of pathogen-infected tpl/tpr mutants and assessments of growth and physiological parameters were employed to determine TPL/TPR roles in transcriptional immunity and defense homeostasis. TPR1 bound to promoter regions of ~1,400 genes and ~10% of the detected binding required EDS1 immunity signaling. A tpr1 tpl tpr4 (t3) mutant displayed mildly enhanced defense-related transcriptional reprogramming upon bacterial infection but not increased bacterial resistance. Bacteria or pep1 phytocytokine-challenged t3 plants exhibited, respectively, photosystem II dysfunction and exacerbated root growth inhibition. Transgenic expression of TPR1 restored the t3 physiological defects. We propose that TPR1 and TPL-family proteins function in Arabidopsis to reduce detrimental effects associated with activated transcriptional immunity.

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Griebel, T., Lapin, D., Locci, F., Kracher, B., Bautor, J., Qiu, J., Concia, L., Benhamed, M., Parker, J. E.. 2021-07-08. Arabidopsis Topless-related 1 mitigates physiological damage and growth penalties of induced immunity. https://doi.org/10.1101/2021.07.07.451397

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