Fig. 5.

Functional reconstitution of ABA activation of SLAC1 channels in (A and B) CPK6- and (C and D) OST1-containing signaling pathways. Current traces (A and C) show examples of the ABA activation of SLAC1 channel currents in oocytes. An ABA-dependent signaling pathway was reconstituted in oocytes using the protein kinases CPK6 (A and B) and OST1 (C and D). Split YFP (BiFC) was used in the case of SLAC1 and OST1 coexpression (C and D). The PP2C phosphatase ABI2 (A and B) or ABI1 (C and D) is able to inhibit SLAC1 currents (blue triangles in B and D). In the absence of ABA, the ABA receptor PYR1 does not activate SLAC1 currents (black hexagons in B and D). However, in the presence of injected ABA, SLAC1 currents are strongly activated (red circles in B and D). Data from one representative batch of oocytes (of >3 batches) are shown in D. Data from two to five independent batches were averaged in B.