biostudies-literatureUnknown45(10)Lempiainen TPhotosynthetic light reactions require strict regulation under dynamic environmental conditions. Still, depending on environmental constraints, photoinhibition of Photosystem (PSII) or PSI occurs frequently. Repair of photodamaged PSI, in sharp contrast to that of PSII, is extremely slow and leads to a functional imbalance between the photosystems. Slow PSI recovery prompted us to take advantage of the PSI-specific photoinhibition treatment and investigate whether the imbalance between functional PSII and PSI leads to acclimation of photosynthesis to PSI-limited conditions, either by short-term or long-term acclimation mechanisms as tested immediately after the photoinhibition treatment or after 24 h recovery in growth conditions, respectively. Short-term acclimation mechanisms were inducePlant, cell & environment2954-2971https://www.ebi.ac.uk/biostudies/studies/S-EPMC9546127biostudies-literaturePlants acclimate to Photosystem I photoinhibition by readjusting the photosynthetic machinery.PMC9546127Lempiainen TRintamaki EAro EMTikkanen MfalsePlants acclimate to Photosystem I photoinhibition by readjusting the photosynthetic machinery.Photosynthetic light reactions require strict regulation under dynamic environmental conditions. Still, depending on environmental constraints, photoinhibition of Photosystem (PSII) or PSI occurs frequently. Repair of photodamaged PSI, in sharp contrast to that of PSII, is extremely slow and leads to a functional imbalance between the photosystems. Slow PSI recovery prompted us to take advantage of the PSI-specific photoinhibition treatment and investigate whether the imbalance between functional PSII and PSI leads to acclimation of photosynthesis to PSI-limited conditions, either by short-term or long-term acclimation mechanisms as tested immediately after the photoinhibition treatment or after 24 h recovery in growth conditions, respectively. Short-term acclimation mechanisms were induce2022-01-01T00:00:00Z2022 Oct2025-04-22T12:04:15.467Z2025-04-06T00:14:00.856ZS-EPMC95461273591619510.1111/pce.14400