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. 2015 Dec 10;170(2):1090–1104. doi: 10.1104/pp.15.01649

Figure 7.

Figure 7.

The kinase activity of CPK33 is required for stomatal closure and the regulation of slow type anion channels. A, In vitro assay of CPK33 kinase activity. Left: Lanes 1 and 2 show the autophosphorylation activity of CPK33-GST in the presence/absence of 1 mm free Ca2+ and the presence of 2 mm EGTA. Right: Lanes 3 and 4 show the phosphorylation of MBP by CPK33-GST. B, In vitro kinase activity of CPK33K102R. Top: The autophosphorylation of purified CPK33-GST and CPK33K102R-GST. Bottom: SDS-PAGE separation of purified CPK33-GST, CPK33K102R-GST, and GST (arrowed). C, ABA-promoted stomatal closure. Error bars represent the se (n = 3). At least 60 stomata were measured for each genotype per replication. D, ABA-activated slow type anion channels in guard cell protoplasts. Time and voltage scales are as shown. E, Current/voltage relationships of whole-cell slow anion currents as illustrated in D. The numbers of guard cells measured were: Col-0 (10), Col-0-ABA (9), CPK33-C-1 (8), CPK33-C-1-ABA (8), CPK33-C-2 (8), CPK33-C-2-ABA (9), CPK33K102R-C-6 (9), CPK33K102R-C-6-ABA (8), CPK33K102R-C-7 (7), and CPK33K102R-C-7-ABA (10). Data are shown in the form mean ± se. Asterisks in C and E indicate significant differences between means (P < 0.05).