500 crosslinker

Whole rosettes of four-week-old-plants grown under an 8 h photoperiod were treated with UV-C radiation. The treatment was performed in a way that ensured each plant to receive the same UV-C dose. A precise amount of UV-C radiation (100 mJ cm⁻²) was applied using a 500 Crosslinker (Hoefer Pharmacia Biotech, San Francisco, CA, USA), equipped with lamps emitting light in the wavelength ranging from 250 to 258 nm (type G8T5, 8W; Sankyo Denki, Hiratsuka, Japan).

UV-C radiation (100 mJ cm^-²) was used as oxidative-stress inducing factor. UV-C radiation was applied with 500 Crosslinker (Hoefer Pharmacia Biotech, San Francisco, CA, USA), equipped with lamps emitting light in the wavelength ranging from 250 to 258 nm (type G8T5, 8W; Sankyo Denki, Hiratsuka, Japan). Cell death analysis was performed by the measurement of ion leakage for 9–12 plants per genotype per treatment in two independent experiments (n=9–12), as previously described (Rusaczonek et al., 2015 (link); Wituszyńska et al., 2015 (link)). Cell death visualization was performed by staining five leaves per genotype per treatment with 1% (m/v) Evans blue and vacuum infiltration for 30 min (Mergemann and Sauter, 2000 (link)). After staining, the leaves were washed three times with deionized water and chlorophyll was removed by the incubation in chloral hydrate (2.5 mg/mL) for two days. The pictures of representative leaves are presented.