a, Schematic illustrating the influence of the MAPK cascade in regulating cell fate specification with the direct connection yet to be demonstrated (question mark). MMC, meristemoid mother cell. b, Yeast two-hybrid (Y2H) assays. Bait: the DNA binding domain alone (DB) and SPCH(ΔN-term). Prey: the activation domain alone (AD), MPK3, MPK6, SCRM and scrm-D. No detectable interaction between MPK3/MPK6 and SPCH is detected. The experiment was repeated independently three times with similar results.
c, Bimolecular Fluorescent Complementation (BiFC) assays. Shown are 3-week old N. benthamiana leaves agroinfiltrated using pairwise combinations of SPCH-YFPn and MPK3-YFPc, MPK6-YFPc along with 35S:: FLAG-SCRM (Scale bars = 25 μm). Right two panels are magnified images of a representative nucleus (scale bars = 10 μm). SPCH does not interact with MPK3/6 by itself but interacts with them only in the presence of SCRM. The experiment was repeated independently three times with similar results.