Supplementary data for the submitted manuscript ‘A broad-host-range Rhizobium rhizogenes strain enables transient expression across diverse crops and establishes functional assays in faba bean’. Data structure: Supplementary Data Fig 2. Betalain quantification for Fig 2B, corrected total cell fluorescence of GFP for Fig 2D, and GFP and mCherry fluorescence for Fig 2F. Supplementary Data Fig 3. HR quantification at 800 nm emission for Fig 3B and 3D. Supplementary Data Fig 4. HR quantification at 800 nm emission for Fig 4B and 4D. Supplementary Data Fig 5. Haustoria counts and fluorescence intensity quantification for Fig 5C. Supplementary Data Fig S1. Betalain quantification for Solanales species in Fig S1. Supplementary Data Fig S2. Betalain quantification for N. tabacum cultivars in Fig S2. Supplementary Data Fig S3. Betalain quantification for Lamiales and Gentianales species in Fig S3. Supplementary Data Fig S4. Betalain quantification for Brassicales and Fabales species in Fig S4. Supplementary Data Fig S5. Betalain quantification for Fig S5B, corrected total cell fluorescence of GFP for Fig S5D, and GFP fluorescence for Fig S5F. Supplementary Data Fig S6. HR quantification for Fig S6A, S6B, S6C and S6D.