A new and totally unexpected fluorescence of PSII discovered - F780
The fluorescence signal from PSII is widely utilized to monitor photosynthetic activity. It is this signal that allows satellites to monitor where things are growing, even in the open ocean.
The complex and strongly temperature dependent fluorescence of PSII has been studied for decades, yet its nature is still being discussed and argued. We have, by identifying and measuring PSII preparations with incredibly low PSI content, including some from recrystallised cyanobacterial PSII samples, been able to identify an entirely new fluorescence system in PSII. We assign this new fluorescence as arising from the 'deep red state' of the reaction centre from its unusually long wavelength (780nm) and excitation dependence.
This is a groundbreaking discovery and will enable many further studies of the unusual lowest energy 'deep red state' of PSII and determine its true function and significance.
Jennifer Morton, Jeremy Hall, Paul Smith, Fusamichi Akita, Faisal Koua, Jian-Ren Shen, Elmars Krausz, Biochemica et Biophysica Acta Bioenergetics 1837 (2014) 167-177