MeJA-induced stomatal closure in Arabidopsis CPK3, CPK6, CPK4, and CPK11 gene disruption mutants. A, MeJA-induced stomatal closure in the wild type (WT) and cpk3-1, cpk6-1, cpk3-1/cpk6-1, cpk4-1, cpk11-2, and cpk4-1/11- 2 mutants. B, MeJA-induced stomatal closure in the cpk6-1 and cpk6-2 mutants. Twenty averages from three independent experiments (60 total stomata per bar) are shown. Error bars represent se.