Fig. 4

Confocal micrographs displaying multiphoton-induced uncaging of CBA in roots of the TCSn::GFP cytokinin reporter line. Roots of 7-day old seedlings were incubated in CBA in the dark for 24 h before irradiation with the 720 nm MP laser. A Transmitted light and reflected GFP fluorescence of root tissue before uncaging. B fluorescence micrograph of the same root, showing GFP signal approximately two hours post uncaging and confined to the irradiated region. C Computational z-section of the same root, produced from a z-stack, demonstrating the vertical specificity of GFP signal, highlighted in dotted white box (as well as background autofluorescence produced in the epidermis). All images captured using 488 nm tuneable argon laser, while uncaging performed using 720 nm MP laser. D Strong GFP signal was detected from the same root using fluorescence optics (470 nm) on a Leica M205FA stereomicroscope approximately four hours after irradiation (region indicated by white arrow)