We collected several hundred root segments (c.0.2 cm) containing infection sites at 10 hpi (migratory stage) and syncytia at 10 dpi (sedentary stage), and analysed GSH1 and GSH2 expression in these tissues compared with uninfected wild‐type Columbia (Col‐0) roots by reverse transcription‐quantitative PCR (RT‐qPCR). The gene discussed is GSX1; the disease is infection.