**2.1 Plant material and growth conditions**

*Chrysanthemum morifolium* (sun plant) and *Spathiphyllum wallisii* (shade plant) were grown in 500 mL pots at 22-25 ºC in the greenhouse with a natural photoperiod, under daytime irradiation maxima of around 800 and 200 mol·m-2·s-1 PPFD (sun and shade plants, respectively) and controlled watering to avoid drought stress (control conditions). To simulate stress conditions, adult plants were transferred to cultivation chambers and exposed to 18 h photoperiods of high light intensity (1060 mol·m-2·s-1 PPFD) supplied by a 100 W Flood Osram (Augsburg, Germany) white light lamp, at 35 ºC, followed by 6h nightperiods at 24 ºC, decreasing the irrigation to 50 mL/day, which was applied after the start the night period.
