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Consequences of photosystem‐I damage and repair on photosynthesis and carbon use in Arabidopsis thaliana
Author(s) -
LimaMelo Yugo,
Gollan Peter J.,
Tikkanen Mikko,
Silveira Joaquim A. G.,
Aro EvaMari
Publication year - 2019
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14177
Subject(s) - photoinhibition , photosynthesis , photosystem ii , photosystem i , carbon fixation , biology , biophysics , botany , photosystem , arabidopsis thaliana , biochemistry , mutant , gene
Summary Natural growth environments commonly include fluctuating conditions that can disrupt the photosynthetic energy balance and induce photoinhibition through inactivation of the photosynthetic apparatus. Photosystem II ( PSII ) photoinhibition is efficiently reversed by the PSII repair cycle, whereas photoinhibited photosystem I ( PSI ) recovers much more slowly. In the current study, treatment of the Arabidopsis thaliana mutant proton gradient regulation 5 ( pgr5 ) with excess light was used to compromise PSI functionality in order to investigate the impact of photoinhibition and subsequent recovery on photosynthesis and carbon metabolism. The negative impact of PSI photoinhibition on CO 2 fixation was especially deleterious under low irradiance. Impaired starch accumulation after PSI photoinhibition was reflected in reduced respiration in the dark, but this was not attributed to impaired sugar synthesis. Normal chloroplast and mitochondrial metabolisms were shown to recover despite the persistence of substantial PSI photoinhibition for several days. The results of this study indicate that the recovery of PSI function involves the reorganization of the light‐harvesting antennae, and suggest a pool of surplus PSI that can be recruited to support photosynthesis under demanding conditions.