Chlorophyll fluorescence measurements
Chlorophyll (Chl) fluorescence was measured at different light regimes to determine Fo, Fm, Fm’, Ft, Fo’, ΦPSII, qP and NPQ, according to (Maxwell & Johnson, 2000), using a FMS-2 Pulse Modulated Fluorimeter (Hansatech Instruments, Norfolk, UK). Plants were sequentially illuminated with 8000 μmol m-2 s1 saturating pulses and 400 μmol m-2 s1 actinic light.