Mutations in SLAC1 suppress expression of several guard cell ion channel and transporter genes. Relative expression of Arabidopsis plasma membrane H+-ATPases AHA1, AHA2, AHA5, transporter AtABCB14 and ion channels KAT1, KAT2, AKT1, AKT2, TPC1, GORK, AtALMT12, and AtKC1 was measured in isolated guard cells of wild type, slac1-1 (dark bars), and slac1-3 (light bars). Error bars indicate ±SEM, n = 4 (*, P < 0.05; °, P < 0.10; One-way ANOVA and LSD test).