Protocol to monitor activation of a two-component system in Dickeya dadantii during chicory leaf infection using...

Quantifying the phosphorylation levels of proteins involved in bacterial signaling pathways is essential for understanding their role in stress adaptation and infection processes. Here, we present a protocol for the semi-quantitative assessment of the phosphorylation level of the transcriptional regulator CpxR during the infection process using Phos-tag gel. We describe steps for Dickeya dadantii infection of chicory leaves, followed by bacterial extraction, rapid acidic cell lysis, and subsequent protein analysis using Phos-tag SDS-PAGE and western blot. For complete details on the use and execution of this protocol, please refer to Bontemps-Gallo et al.¹ and Cochard et al.².