Fig. 8.

Analysis of quenching yields subjected to a stepwise increase in irradiance (data Fig. 3). a Top panel NPQ calculated using the Stern–Volmer equation ((F _m − F _m′)/F _m′), and as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\text{NPQ}}_{{\sigma_{\text{PSII}} }} $$\end{document} ((σ_PSII − σ_PSII′)/σ_PSII′). Bottom panel regulated NPQ (Φ_NPQ) and constitutive NPQ (Φ_f,D). b Relationship between σ_PSII (bottom X-axis) and the two proxies for the NPQ (left Y-axis) or the quantum efficiency for constitutive NPQ (right Y-axis)