Frequently asked questions about chlorophyll fluorescence, the sequel

Abstract

Using chlorophyll (Chl) a fluorescence many aspects of the photosynthetic apparatus can be studied, both in vitro and, noninvasively, in vivo. Complementary techniques can help to interpret changes in the Chl a fluorescence kinetics. Kalaji et al. (Photosynth Res 122:121–158, 2014a) addressed several questions about instruments, methods and applications based on Chl a fluorescence. Here, additional Chl a fluorescence-related topics are discussed again in a question and answer format. Examples are the effect of connectivity on photochemical quenching, the correction of F V/F M values for PSI fluorescence, the energy partitioning concept, the interpretation of the complementary area, probing the donor side of PSII, the assignment of bands of 77 K fluorescence emission spectra to fluorescence emitters, the relationship between prompt and delayed fluorescence, potential problems when sampling tree canopies, the use of fluorescence parameters in QTL studies, the use of Chl a fluorescence in biosensor applications and the application of neural network approaches for the analysis of fluorescence measurements. The answers draw on knowledge from different Chl a fluorescence analysis domains, yielding in several cases new insights.

Non-intrusive Assessment of Photosystem II and Photosystem I in Whole Coral Tissues

“…This method consists of monitoring the kinetics of the chlorophyll induction curve in the transition between dark to light adapted state (Kalaji et al, 2017). This protocol primary measures the transition between the point where all PSII reaction center are open (refer as O step or F o at 20 µs) to the point where all reaction centers are closed and the fluorescence intensity reaches its maximum, nominally called Peak (refer as P step or F m ) (Strasser, 1992).…”

“…Additionally, two inflections can be observed at 2 ms (J step) and at 20 ms (I step). These four steps delimit three phases: OJ, JI and IP and conventionally it is believed that they are associated with events in the electron transport chain (ETC) (Strasser, 1992;Kalaji et al, 2017). The OJ, photochemical phase, relates to the reduction of the acceptor side of PSII (Strasser, 1992).…”

“…The OJ, photochemical phase, relates to the reduction of the acceptor side of PSII (Strasser, 1992). The JI phase relates to the transport beyond Q A and IP phase relates to several processes, in particular the electrons reaching PSI (Schansker et al, 2005;Kalaji et al, 2017). The induction curve of the chlorophyll a fluorescence (OJIP transient) was measured at 25 • C using a Multichannel-Plant Efficiency Analyzer 2 (M-PEA, Hansatech Instruments, UK) (for a full description of the instrument refer to Strasser et al, 2010).…”

Effect of environmental factors on growth and physiological status of generative shoots of Cladium mariscus in a protected calcareous fen habitat

“…Currently chlorophyll a fluorescence measurements are widely used in many physiological and ecophysiological studies (Maxwell, Johnson 2000;Kalaji et al 2016), as they provide insight in plant primary photochemistry and in plant physiological response to both short-term and longterm changes in environmental conditions, including severe temperature changes, water and drought stress etc. The most frequently used chlorophyll a fluorescence parameter is maximum quantum yield of photosystem II photochemistry (F v /F m ) (Kalaji et al 2017).…”

Rooting affects the photosystem II activity: in vitro and ex vitro studies on energy hybrid sorrel

“…Analysis of the chlorophyll a fluorescence induction curves allows to determine physiological conditions that affect photosynthetic electron transport chain in the proximity of PSII (Baker 2008;Murchie and Lawson 2013;Kalaji et al 2014Kalaji et al , 2016Kalaji et al , 2017.…”