ATP‐induced chlorophyll luminescence in isolated spinach chloroplasts

Upon a light-dark transition chloroplasts emit post-illumination luminescence [l] , which is commonly considered to result from the recombination of positive charges (Z’) and negative charges (Q-) at the photosystem II reaction centers [ 1,2] . Stimulation of post-illumination luminescence by a variety of treatments has been reported (for a recent review, see [3]) such as transthylakoidal ApH [4], ApH-reduced, reverse electron flow [S] , salt addition [6], a rapid temperature increase {7], addition of DCMU [8] or dithionite [9]. These treatments have in common, that they either increase the supply of electrons at Q or provide an additional source of activation energy for the recombination reaction (see [31). After light-activation of the latent adenosine triphosphatase (ATPase), addition of ATP in the dark to isolated chloroplasts leads to formation of a transthylakoidal ApH (see [lo]) and reduction of Q by reverse electron flow [ 11,121. In this report we wish to describe a procedure by which ATP-induced luminescence can be readily