Topless corepressors as an emerging hub of plant pathogen effectors.

Transcriptional corepressors form an ancient and essential layer of gene expression control in eukaryotes. TOPLESS and TOPLESS-RELATED (TPL)/TPR) proteins constitute a conserved family of Groucho (Gro) / Thymidine uptake 1 (Tup1) type transcriptional corepressors and control diverse growth, developmental, and stress signalling responses in plants. Due to their central and versatile regulatory roles, they act as a signalling hub to integrate various input signalling pathways in the transcriptional responses. Recently, increasing pieces of evidence indicate the roles of TPL/TPR family proteins in the modulation of plant immunity. This is supported by studies on effectors of distantly related pathogens that target TPL/TPR proteins in planta. In this short review, we will summarize the latest findings where pathogens target plant TPL/TPR proteins to manipulate plant signalling responses for the successful invasion of their hosts.