Spillover in the direct-type PSI-PSII megacomplex isolated from Arabidopsis thaliana is regulated by pH.

Various megacomplexes in which Photosystem I and Photosystem II are physically bound (PSI-PSII m.c.) have been found in many organisms. In terms of function, these can be divided into two groups: those in which PSII and PSI are closely coupled (direct-type, photoprotection), and those in which a large light-harvesting antenna is placed between PSII and PSI (bridged-type, energy sharing). Arabidopsis thaliana has been reported to use the direct-type, where fast energy transfer occurs from PSII to PSI (~20 ps, fast spillover). In this paper, we show that the fast spillover is reversibly regulated depending on pH.
Competing Interests: Declaration of competing interest M.Y. applied for a patent on a method to rapidly quantify the PSI-PSII megacomplex and reduce its accumulation, thereby reducing costs in plant factories. https://www.j-platpat.inpit.go.jp/c1800/PU/JP-2022-151463/9F237D5099C9FFA71C4423F3D6DF0DDE613FA94BE2CC53DE716CB8F043AA5573/11/en.
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