REVIEW Chlorophyll thermofluorescence and thermoluminescence as complementary tools for the study of temperature stress in plants Jean-Marc Ducruet Æ Violeta Peeva Æ Michel Havaux Received: 31 August 2006 / Accepted: 4 January 2007 / Published online: 6 February 2007 Ó Springer Science+Business Media B.V. 2007 Abstract The photosynthetic apparatus, especially the electron transport chain imbedded in the thylakoid membrane, is one of the main targets of cold and heat stress in plants. Prompt and delayed fluorescence emission originating from photosystem II have been used, most often separately, to monitor the changes induced in the photosynthetic membranes during pro- gressive warming or cooling of a leaf sample. Ther- mofluorescence of F 0 and F M informs on the effects of heat on the chlorophyll antennae and the photochem- ical centers, thermoluminescence on the stabilization and movements of charges and Delayed Light Emis- sion on the permeability of the thylakoid membranes to protons and ions. Considered together and operated simultaneously, these techniques constitute a powerful tool to characterize the effect of thermal stress on intact photosynthetic systems and to understand the mechanisms of constitutive or induced tolerance to temperature stresses. Abbreviations AG Afterglow E a Activation energy of charge recombination DLE Delayed light emission (luminescence under modulated excitation) F 0 Minimum fluorescence level F M Maximum fluorescence level F 0 /T curve Temperature dependence curve of steady-state chlorophyll fluorescence excited by a dim light LHCII Light-harvesting complex II PS-II Photosystem II P 680 PS-II reaction center chlorophyll Q A ,Q B Primary and secondary quinonic acceptors of photosystem II S1, S2, S3 State of the manganese oxygen-evolving complex storing 1, 2, 3+ charges resp. T c Critical temperature above which chlorophyll fluorescence starts to rise sharply in the F 0 /T curve T m Maximal temperature of a TL band TL Thermoluminescence Introduction Plant species have different optimal temperature domains, initially determined by their geographical origin. Long-term adaptation to warmer or cooler cli- mates produced natural ecotypes (or, by breeding, cultivars of crop plants) more tolerant to heat or cold than their original ancestors. Plants are also able of J.-M. Ducruet (&) Service de Bioe ´ nerge ´ tique, INRA-CEA Saclay, 91191 Gif-sur-Yvette cedex, France e-mail: jean-marc.ducruet@cea.fr J.-M. Ducruet ESE, Biospectroscopie Ve ´ge ´ tale, Universite ´ Paris-Sud, 91405 Orsay, France V. Peeva Institute of Plant Physiology, BAS, G. Bonchev str., Bl. 21, Sofia 1113, Bulgaria M. Havaux CEA/Cadarache, DSV, IBEB, SBVME, Laboratoire d’Ecophysiologie Mole ´ culaire des Plantes, UMR 6191 CNRS-CEA-Aix Marseille Univ., 13108 Saint-Paul-lez- Durance, France 123 Photosynth Res (2007) 93:159–171 DOI 10.1007/s11120-007-9132-x