The coding sequence of the NopL was cloned into pET28a vector using BamH I and Sal I restriction enzymes. The resulting vector was transformed into E. coli BL21 (DE3) for the expression of recombinant protein. His-NopL protein was purified by Ni NTA Beads 6FF (Smart-lifesciences, SA005005). DN50 roots inoculated with HH103 were collected at 1 dpi and frozen in liquid nitrogen. Soybean root hair cells were collected by scraping the soybean roots using the cell scraper (Corning Incorporated, 3010). Soybean root hair proteins were extracted using protein extraction buffer (50 mM Tris-HCl pH 7.5, 150 mM NaCl, 10% Glycerol, 0.2% Trixton X-100, 1 mM DTT, 1×protease inhibitor cocktail, 1 mM NaF, 1 mM Na3VO4 and 1 mM PMSF). The obtained His-NopL protein was added to the soybean root protein extract, while no His-NopL protein was added to the control sample. After mixing, the NopL interacting proteins were pull-down using Ni NTA Magarose Beads (Smart-lifesciences, SM008001) semi-in vivo. Finally, the eluted proteins were subjected to analysis using LC-MS/MS to identify and characterize the proteins that interact with NopL.