Light‐induced stomatal movement of selected Arabidopsis thaliana mutants

Various Arabidopsis thaliana mutants with defects in phytohormone signal transduction or the reception of light were analysed with regard to their stomatal response in a red, red/blue light irradiation programme. Stomatal response to light was detected with a customized gas exchange measurement device, optimized for the small model plant. Small transpiration-kinetic variations of the two wild-type lines Columbia (Col) and Landsberg erecta (Ler) were observed. A comparison of the mutant lines to the respective wild type revealed significant differences for the phytochrome A (phyA-103), the abscisic acid insensitive (aba3-2) and the auxin resistant (axr1-3) mutant. Furthermore, the zeaxanthin-less mutant line npq1-2 showed no alterations in stomatal response to light.