In this section
@article{Fantuzzi:2023:plphys/kiad275,
author = {Fantuzzi, A and Haniewicz, P and Farci, D and Loi, MC and Park, K and Büchelf, C and Bochtler, M and Rutherford, A and Piano, D},
doi = {plphys/kiad275},
journal = {Plant Physiology},
pages = {2656--2671},
title = {Bicarbonate activation of the monomeric photosystem II-PsbS/Psb27 complex},
url = {http://dx.doi.org/10.1093/plphys/kiad275},
volume = {192},
year = {2023}
}
TY - JOUR
AB - In thylakoid membranes, Photosystem II (PSII) monomers from the stromal lamellae contain the subunits PsbS and Psb27 (PSIIm-S/27), while PSII monomers from granal regions (PSIIm) lack these subunits. Here, we have isolated and characterised these two types of Photosystem II complexes in tobacco (Nicotiana tabacum). PSIIm-S/27 showed enhanced fluorescence, the near-absence of oxygen evolution, as well as limited and slow electron transfer from QA to QB compared to the near-normal activities in the granal PSIIm. However, when bicarbonate was added to PSIIm-S/27, water splitting and QA to QB electron transfer rates were comparable to those in granal PSIIm. The findings suggest that the binding of PsbS and/or Psb27 inhibits forward electron transfer and lowers the binding affinity for bicarbonate. This can be rationalized in terms of the recently discovered photoprotection role played by bicarbonate binding via the redox tuning of the QA/QA•– couple, which controls the charge recombination route, and this limits chlorophyll triplet mediated 1O2 formation. These findings suggest that PSIIm-S/27 is an intermediate in the assembly of PSII in which PsbS and/or Psb27 restrict PSII activity while in transit using a bicarbonate-mediated switch and protective mechanism.
AU - Fantuzzi,A
AU - Haniewicz,P
AU - Farci,D
AU - Loi,MC
AU - Park,K
AU - Büchelf,C
AU - Bochtler,M
AU - Rutherford,A
AU - Piano,D
DO - plphys/kiad275
EP - 2671
PY - 2023///
SN - 0032-0889
SP - 2656
TI - Bicarbonate activation of the monomeric photosystem II-PsbS/Psb27 complex
T2 - Plant Physiology
UR - http://dx.doi.org/10.1093/plphys/kiad275
UR - http://hdl.handle.net/10044/1/104247
VL - 192
ER -
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