Light-induced stomatal movement of selected Arabidopsis thaliana mutants

Various Arabidopsis thaliana mutants with defects in phytohormone signal tr ansduction or the reception of light were analysed with regard to their sto matal response in a red, red/blue light irradiation programme, Stomatal res ponse to light was detected with a customized gas exchange measurement devi ce, optimized for the small model plant. Small transpiration-kinetic variat ions of the two wild-type lines Columbia (Col) and Landsberg erecta (Ler) w ere observed. A comparison of the mutant lines to the respective wild type revealed significant differences for the phytochrome A (phyA-109), the absc isic acid insensitive (aba3-2) and the auxin resistant (axr1-3) mutant. Fur thermore, the zeaxanthin-less mutant line npq1-2 showed no alterations in s tomatal response to light.