The afterglow photosynthetic luminescence

The afterglow (AG) photosynthetic luminescence is a long-lived chlorophyll fluorescence emitted from PSII after the illumination of photosynthetic materials by FR or white light and placed in darkness. The AG emission corresponds to the fraction of PSII centers in the S(2/3)Q(B) non-radiative state immediately after pre-illumination, in which the arrival of an electron transferred from stroma along cyclic/chlororespiratory pathway(s) produces the S(2/3)Q(B)(-) radiative state that emits luminescence. This emission can be optimally recorded by a linear temperature gradient as sharp thermoluminescence (TL) band peaking at about 45 degrees C. The AG emission recorded by TL technique has been proposed as a simple non-invasive tool to investigate the chloroplast energetic state and some of its metabolism processes as cyclic transport of electrons around PSI, chlororespiration or photorespiration. On the other hand, this emission has demonstrated to be a useful probe to study the effect of various stress conditions in photosynthetic materials.

Automated summary

The afterglow photosynthetic luminescence, known as AG emission, is a long-lived chlorophyll fluorescence emitted from PSII. It can be recorded by TL technique and used to study the energetic state and metabolism processes of the chloroplast, as well as the impact of various stress conditions on photosynthetic materials.