Fig. 1

Pictures illustrating the described transformation procedure. a Roots from 5-day-old L. japonicus MG20 seedlings were removed. The arrow indicates the cutting site at the bottom of the hypocotyl. Seedlings were co-cultivated with A. rhizogenes for 30 min. c Seedlings were transferred to agar plates containing ½ strength Gamborg’s B5 Salts and Vitamins medium. d The agar with seedlings was covered with a sterile filter paper and the plate sealed with parafilm. e Plants were weekly transferred to a fresh agar plate and covered by a new filter paper. f Analysis by fluorescence microscopy (28 dpi): Selected plants showing at least one red fluorescent root were placed into plastic jar units and inoculated with M. loti MAFF303099. g Plants with formed nodules (arrow) were harvested 4 weeks later. h Analysis of roots and nodules by fluorescence microscopy. The picture shows a red fluorescent root with two nodules. Bars = 1 mm in a, 1 cm in b, 2 cm in c–e, 500 μm in f, 2 cm in g, and 500 μm in h