Abstract: The present invention relates to a system (1) for infiltrating plant tissue with macromolecules or microorganisms. The system comprises an infiltration chamber (2) having at least one sealable hatch for receiving plant tissue, means (P1) for reducing pressure within the infiltration chamber; a first release valve (V1) in fluid communication with the infiltration chamber. The system further comprises a controller (C1) for operating coordinately the first release valve and the pressure reducing means such that the pressure in the infiltration chamber is (i) reduced from a start pressure to a target pressure that is less than or equal to 300 mbar in a first time period, (ii) maintained at the target pressure for a second time period, and (iii) increased from the target pressure to a final pressure of at least approximately 1 bar within a third time period of less than or equal to five (5) seconds. The present invention also relates to a method of infiltrating plant tissue with bacterium cells.