Figure 5.

Sulfate-Induced Stomatal Closure Requires Sulfate Reduction and Incorporation of Sulfide into Cys.

(A) and (B) Impact of ABA (gray, 50 µM) and sulfate (white, 15 mM MgSO₄) on hydrogen peroxide production in guard cells of sir1-1 (A) and serat tko (B) plants. Data represent mean ± se (n ≥ 100; derived from ≥5 individual plants).

(C) Impact of ABA (gray, 50 μM) and sulfate (white, 15 mM MgSO₄) on the stomatal apertures of the wild type (WT) and of mutants with a strongly reduced ability to reduce sulfate to sulfide (sir1-1) or incorporate sulfide into Cys (serat tko). Control refers to water. Data represent mean ± sd in (C) (n ≥ 50 stomata, derived from ≥5 individual plants).

Letters indicate statistically significant differences between groups determined with one-way ANOVA (P < 0.05).