Protocol:

To reach an optical density (OD600) of ~0.6-0.9, R. radiobacter cells were cultivated at 28 °C. After centrifuging the cells for 15 min at 3000 x g and 4 °C, the precipitate was kept and dissolved in infiltration medium. In contrast to the first dissolving agent, the infiltration medium for the second preparation step contained acetosyringon additionally. For the infiltration of plant leaves, syringes were loaded with 2 ml bacteria suspension. With low but constant pressure, R. radiobacter cells were injected into the leaf tissue. Treated plants were covered for 2 d. If the plants were not directly available, the prepared bacteria cells were stored at 4 °C temporarily.