PM Plasma Membrane PTI Pattern-Triggered Immunity SpC Spectral Count(s)

The plant plasma membrane is a crucial mediator of the interaction between plants and microbes. Understanding how the plasma membrane proteome responds to diverse immune signaling events will lead to a greater understanding of plant immunity and uncover novel targets for crop improvement. Here we report the results from a large-scale quantitative proteomics study of plasma membrane-enriched fractions upon activation of the Arabidopsis thaliana immune receptor RPS2. More than 2300 proteins were identified in total with 1353 proteins reproducibly identified across multiple replications. Label-free spectral counting was employed to quantify relative protein abundance between different treatment samples. Over 20 % of upregulated proteins have known roles in plant immune responses. Significantly changing proteins include those involved in calcium and lipid signaling, membrane transport, primary and secondary metabolism, protein phosphorylation, redox homeostasis, and vesicle trafficking. A subset of differentially regulated proteins was independently validated during bacterial infection. This study presents the largest quantitative proteomics dataset of plant immunity to date and provides a framework for understanding global plasma membrane proteome dynamics during plant immune responses