Modeling chlorophyll a fluorescence transient: Relation to photosynthesis

Abstract

To honor Academician Alexander Abramovitch Krasnovsky, we present here an educational review on the relation of chlorophyll a fluorescence transient to various processes in photosynthesis. The initial event in oxygenic photosynthesis is light absorption by chlorophylls (Chls), carotenoids, and, in some cases, phycobilins; these pigments form the antenna. Most of the energy is transferred to reaction centers where it is used for charge separation. The small part of energy that is not used in photochemistry is dissipated as heat or re-emitted as fluorescence. When a photosynthetic sample is transferred from dark to light, Chl a fluorescence (ChlF) intensity shows characteristic changes in time called fluorescence transient, the OJIPSMT transient, where O (the origin) is for the first measured minimum fluorescence level; J and I for intermediate inflections; P for peak; S for semi-steady state level; M for maximum; and T for terminal steady state level. This transient is a real signature of photosynthesis, since diverse events can be related to it, such as: changes in redox states of components of the linear electron transport flow, involvement of alternative electron routes, the build-up of a transmembrane pH gradient and membrane potential, activation of different nonphotochemical quenching processes, activation of the Calvin-Benson cycle, and other processes. In this review, we present our views on how different segments of the OJIPSMT transient are influenced by various photosynthetic processes, and discuss a number of studies involving mathematical modeling and simulation of the ChlF transient. A special emphasis is given to the slower PSMT phase, for which many studies have been recently published, but they are less known than on the faster OJIP phase.

Thylakoid membrane model of the Chl a fluorescence transient and P700 induction kinetics in plant leaves

“…The intermediate dip S, between peak P and local maximum M, is pronounced when the total OJIPSMT kinetics displays the two-wave pattern. The slow SMT wave shows details (Papageorgiou et al 2007;Stirbet et al 2014;Kodru et al 2015), which are different in higher plants, algae or cyanobacterial samples.…”

“…However, the photosynthesis models were constructed to describe the PSII mechanisms on a wider time scale (s) in a simplified form, by taking into account only certain ETC processes (Kroon and Thoms 2006;Laisk et al 2006). The model analysis was also applied to explain the membrane energization coupled to the pH factors (Kuvykin et al 2011), or to investigate the pH-activated nonphotochemical fluorescence quenching (NPQ) (Ebenhöh et al 2011;Stirbet et al 2014). The Calvin-Benson cycle reactions were described also (Laisk and Walker 1989;Laisk et al 2006;Zhu et al 2013).…”

Systems approach to excitation-energy and electron transfer reaction networks in photosystem II complex: model studies for chlorophyll a fluorescence induction kinetics

“…EDSTs also presume the quenchers of fluorescence in addition to the Q A in oxidized state since various quenchers have been proposed. While the accuracy of the model calculations to reproduce the experimental results has thus been improved substantially (Stirbet et al, 2014), it has become fairly difficult to intuitively and comprehensively understand the whole phenomena. On the other hand, a totally different, phenomenological model accounting for the FI behaviors has also been proposed by Vredenberg (2000), Prášil (2009), Vredenberg (2011).…”

The influence of phosphite treatments on oak leaves and damage caused by powdery mildew Erysiphe alphitoides

“…The chlorophyll a fluorescence process can provide information on the functioning and structure of the photosynthetic apparatus (Kalaji and Łoboda 2007;Akhkha et al 2013;Stirbet et al 2014;Živčák et al 2014). Moreover, the methods based on records of chlorophyll fluorescence are reliable, non-invasive, powerful and simple tools for the assessment of photosynthetic electron transport (Živčák et al 2014) and related photosynthetic processes and allow detection of stress in plants (Baker and Rosenqvist 2004;BorawskaJarmułowicz et al 2014).…”