... Trois-Rivie`res,Que´bec, Canada G9A 5H7Fax: +1 819 376 5057E-mail: Robert.Carpentier@uqtr.ca(Received 17 May 20 06, revised 10 July 20 06, accepted 22 August 20 06)doi :10 .11 11/ j .17 42- 4658 .20 06.05475.xFluorescence ... nonphotochemical quenching; PQ, plastoquinone; PS, photosystem; QA and QB, primary and secondary quinone acceptors of photosystem II; t 1 ⁄ 2 O–J, t 1 ⁄ 2 J–I and t 1 ⁄ 2 I–P, half-times of ... the acceptor side of PSII [9 , 12 ,13 ], or morespecifically to the reduction of two distinct plastoqui-none (PQ) pools [8 ,14 ,15 ]. Schreiber [11 ] also proposedthat the J–I phase is related to the...