*4.2. Determination of Protein Localization in Nicotiana benthamiana*

For transient transformation of *Nicotiana benthamiana* plants, *Agrobacterium tumefaciens* cells of the strain GV3101 pMP90 harboring the respective c-terminal YFP-tagged PK-CDS were grown overnight in a 25 mL culture (YEB, 100 ng/μL carbenicillin, 25 ng/μL gentamycin, 12 ng/μL kanamycin, 100 ng/μL rifampicin). Cells were harvested by centrifugation at 4000× *g* for 10 min and 4 ◦C, re-suspended in 1 mL infiltration medium (5% *w*/*v* sucrose, 0.01% *v*/*v* Silwet l-77, 2 mM MgSO4, 0.5% *w*/*v* glucose, 450 μM acetosyringone), and OD600 was adjusted to 0.4. After incubation for at least 1 h on ice, and subsequent warming to room temperature, the suspension was infiltrated at the lower side of the tobacco leaves using a 1 mL blunt end tip syringe. For determination of enzyme localization, leaf samples were taken three to four days after infiltration and analyzed by confocal laser scanning microscopy using a Zeiss

LSM 700 microscope. LAS AF imaging software (Leica Application Suite Advanced Fluorescence, Leica) was used for image processing and documentation.
