Proc Natl Acad Sci U S A. 2008 April 1; 105(13): 5271–5276
Fig. 1. Absence of inward K+ channel activity in guard cells of the kincless mutant. (A) Representative macroscopic current traces recorded with the patch-clamp technique in guard cell protoplasts from WT (Upper Left), kat2-1 (knockout mutant disrupted in the KAT2 gene) (Upper Right), domneg-1 (expressing a dominant negative kat2 construct in WT background) (Lower Right), or kincless (expressing the same domneg construct in the kat2-1 background) (Lower Left) plants. In all recordings, the holding potential was −100 mV; voltage steps were applied to potentials ranging between −100 and +120 mV in 20-mV increments (top traces for each genotype) or between −100 and −260 mV in increments of −20 mV (bottom traces for each genotype). (B) Comparison of current–voltage relationships from the different genotypes. Total current (I tot, sampled at time marked by symbols over the recordings in A) is plotted against membrane potential. Data are means ± SE (with the number of repeats in brackets). Proc Natl Acad Sci U S A. 2008 April 1; 105(13): 5271–5276
Proc Natl Acad Sci U S A. 2008 April 1; 105(13): 5271–5276
Fig. 5. Disruption of inward K+ channel activity affects stomatal circadian rhythm and renders stomatal opening sensitive to the duration of the preceding photoperiods. (A and B) Effect on stomatal circadian rhythm. (A) Continuous recording of the transpiration rate in a single WT or kincless plant during 7 days. Black and white boxes under the curves indicate dark and light periods, respectively. Two photoperiods were suppressed, on days 4 and 5. (B) Enlargement from A (dotted boxed regions) highlighting stomatal preopening in darkness in the WT plant. (C and D) Sensitivity to the duration of the preceding photoperiods. (C) Transpiration rates recorded in 5-week-old WT or kincless plants exposed to an 8-h photoperiod since sowing. (D) Transpiration rates recorded in the same plants after exposure to a 3-h photoperiod during 2 days. Data are means ± SE; n = 15 plants per genotype. Proc Natl Acad Sci U S A. 2008 April 1; 105(13): 5271–5276
