The Mathematical Biology of Diatoms

13A Generalized Model for the Light Response of the Nonphotochemical Quenching of Chlorophyll Fluorescence of Diatoms

João Serôdio¹* and Johann Lavaud²

¹ Department of Biology, Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal

² Laboratoire des Sciences de l’Environnement Marin – LEMAR (UMR 6539), CNRS/Univ Brest/Ifremer/IRD, Institut Européen de la Mer-IUEM, Plouzané, France

Abstract

As photoautotrophs, diatoms have developed photoprotective mechanisms to deal with excessive ambient light and to minimize photodamage to the photosynthetic apparatus. Most of these mechanisms rely on energy-dissipation processes, collectively named non-photochemical quenching of fluorescence (NPQ). The functioning of these photoprotective processes is commonly characterized by generating light-response curves of NPQ (“NPQ light curves”), which provide a detailed and ecologically relevant description of how the energy dissipating pathways are activated or relaxed as ambient light intensity varies. The light curves (LCs) are constructed by evaluating NPQ at different light intensities, by measuring the emission of chlorophyll a fluorescence in vivo, typically using a noninvasive technique called pulse amplitude modulation (PAM) fluorometry. NPQ LCs have been quantitatively described by the three-parameter mathematical model of Serôdio and Lavaud (2011), which adequately describes the monotonic rise of NPQ with light intensity, observed in many conditions ...