Gene expression evolution in pattern-triggered immunity within <i> Arabidopsis thaliana </i> and across Brassicaceae species

Abstract

'Anna Piasecka' 'Baoxing Song' 'Eik Dahms' 'Hitoshi Sakakibara' 'Xiangchao Gan' 'Karolina Kułak' 'Aneta Sawikowska' 'Paweł Krajewski' 'Miltos Tsiantis' 'Ruben Garrido-Oter' 'Kenji Fukushima' 'Paul Schulze-Lefert' 'Stefan Laurent' 'Paweł Bednarek' 'Kenichi Tsuda'] Title: Abstract Plants recognize surrounding microbes by sensing microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). Despite their significance for microbial control, the evolution of PTI responses remains largely uncharacterized. Here, by employing comparative transcriptomics of six Arabidopsis thaliana accessions and three additional Brassicaceae species to investigate PTI responses, we identified a set of genes that commonly respond to the MAMP flg22 and genes that exhibit species-specific expression signatures. Variation in flg22-triggered transcriptome responses across Brassicaceae species was incongruent with their phylogeny, while expression changes were strongly conserved within A. thaliana. We found the enrichment of WRKY transcription factor binding sites in the 5′-regulatory regions of conserved and species-specific responsive genes, linking the emergence of WRKY-binding sites with the evolution of gene expression patterns during PTI. Our findings advance our understanding of the evolution of the transcriptome during biotic stress.