Plants were cultivated as described previously37 (link), with some modifications. In brief,
Arabidopsis thaliana Columbia-0 (Col-0) seeds were
surface-sterilized67 and stratified for 4 days at 4°C. Plants were cultivated in six- or
twelve-well tissue culture plates (TechnoPlasticProducts) filled with 5 or 2 ml
washed and heat-sterilized calcined clay and 2.5 or 1 ml half-strength Murashige
& Skoog medium pH 5.8 including vitamins (½ MS, Duchefa),
respectively. Individual seeds were placed in the center of each well. If seeds
did not germinate, a seedling was transplanted to the corresponding well six
days after seeding. Starting at day 6, each well was supplemented twice per week
with 200 or 100 μL ½ MS, respectively. Plates were incubated in a
growth chamber (Percival, CU41-L4) set to 22°C and 54% relative humidity
with a 11 h light 13 hours dark regime fitted with full spectrum lights (Philips
Master TL-D 18W/950 Graphica) and lights emitting a higher fraction of UVA and
UVB (Sylvania Reptistar F18W/6500K). Combined light intensity was set to 200-210
µmol m-2 s-1 for wavelength 400-700 nm and 4-5
µmol m-2 s-1 for wavelength 280-400 nm.
Arabidopsis thaliana Columbia-0 (Col-0) seeds were
surface-sterilized67 and stratified for 4 days at 4°C. Plants were cultivated in six- or
twelve-well tissue culture plates (TechnoPlasticProducts) filled with 5 or 2 ml
washed and heat-sterilized calcined clay and 2.5 or 1 ml half-strength Murashige
& Skoog medium pH 5.8 including vitamins (½ MS, Duchefa),
respectively. Individual seeds were placed in the center of each well. If seeds
did not germinate, a seedling was transplanted to the corresponding well six
days after seeding. Starting at day 6, each well was supplemented twice per week
with 200 or 100 μL ½ MS, respectively. Plates were incubated in a
growth chamber (Percival, CU41-L4) set to 22°C and 54% relative humidity
with a 11 h light 13 hours dark regime fitted with full spectrum lights (Philips
Master TL-D 18W/950 Graphica) and lights emitting a higher fraction of UVA and
UVB (Sylvania Reptistar F18W/6500K). Combined light intensity was set to 200-210
µmol m-2 s-1 for wavelength 400-700 nm and 4-5
µmol m-2 s-1 for wavelength 280-400 nm.