Silwet l 77

Stomatal conductance was measured with an AP4 Porometer (Delta-T Devices, Cambridge, UK). Two leaves were analysed from five different individual plants for each genotype and the experiment was repeated with similar results five times.
For water loss measurements according to Leung et al. 1997 [77 (link)]; three detached rosette leaves of max2-1, max2-4 and wild-type Col-0 plants were incubated abaxial face up at ambient laboratory conditions. Fresh weight of the detached leaves was measured at various time points for 240 min. Water loss was expressed as percentage of initial fresh weight upon excision. Five individual plants were used for each genotype and the experiment was repeated with similar results five times.
Stomatal responses to exogenous ABA (Additional file 1: Figure S2) and to 3 h 350 nmol/mol ozone exposure were measured with the custom made eight-chamber whole-plant rapid-response gas exchange measurement device described previously [50 (link)]. Standard conditions during the stabilization were: ambient CO₂ (c. 400 ppm), light 150 μmol m⁻² s⁻¹, RH 60–70%. Distilled water with 0,012% Silwet L-77 (Duchefa) and with or without 5 μM of abscisic acid was sprayed onto intact Arabidopsis rosettes, air-dried in the measurement cuvette and 7 min after spraying stomatal conductance was recorded for the next 40 min.