Regulation of light capture
ATP-dependent zinc metalloprotease (FtsH) 4 and FtsH 2, both involved
in
“PSII
associated light-harvesting complex II
(LHCII) catabolic process”,
were significantly upregulated
(Fig. 2A). Three proteins responsible for
antenna assembly, including LHCII
protein Lhcb3, low PSII
accumulation 3 (LPA3) assisting chlorophyll a binding protein CP43
assembly within PSII, and PsaH binding light-harvesting complex I
protein Lhca2 to PSI core complex
(Table S1), were downregulated,
suggesting a decrease of antenna size following light exposure.
The distinct interactions of PsbO
with Lhcb3, PsaH
were shown in the PPI network,
indicating the potential of OEC to regulate antenna assembly (Fig.
2B).
Regulation of electron
transport
Proteome data revealed that the
proteins involved in PSII assembly,
such as high chlorophyll
fluorescence phenotype244 (HCF244), domain of unknown function (DUF1995)
and thylakoid formation 1 (THF1), displayed upregulation expression,
indicating that continuous repair was required to retain PSII
functionality. The proteins involved in electron donating to PSI
reaction center P700+, such as proton gradient
regulation 5 (PGR5) and PsaN, were
also upregulated, indicating the
activation of the PGR5-dependent PSI-CEF (Fig. 2A). In addition, the
protein called acclimation of photosynthesis to environment was
upregulated, contributing to the acclimation of photosynthetic electron
transfer to illumination (Table S1).
The
interactions between PsbO and HCF244, as well as PGR5 and PsaN, shown in
the PPI network, suggested the need of electron transport regulation due
to the partially impaired OEC (Fig. 2B).