Nonphotochemical quenching measurements

NPQ was calculated as (Fm-Fm′)/Fm′ (Bilger & Björkman, 1990) using a Dual PAM‐101 (Waltz, Effeltrich, Germany). F _m is the maximum Chl fluorescence emitted by dark‐adapted cells after 2 min treatment with a far‐red LED, Fm′ is the maximum fluorescence measured upon exposure to actinic light or during dark recovery. Far‐red light was turned on also during dark recovery. A 5000 µmol m⁻² s⁻¹ saturation pulse was used to induce F _m and Fm′ while the intensity of the actinic lights used were reported in the results section.