Journal article
Defects in the Expression of Chloroplast Proteins Leads to H2O2 Accumulation and Activation of Cyclic Electron Flow around Photosystem I
Frontiers in plant science, Vol.7, pp.2073-2073
01/13/2017
Handle:
https://hdl.handle.net/2376/110019
PMCID: PMC5233679
PMID: 28133462
Abstract
We describe a new member of the class of mutants in Arabidopsis exhibiting high rates of cyclic electron flow around photosystem I (CEF), a light-driven process that produces ATP but not NADPH. High cyclic electron flow 2 (
hcef2
) shows strongly increased CEF activity through the NADPH dehydrogenase complex (NDH), accompanied by increases in thylakoid proton motive force (
pmf
), activation of the photoprotective q
E
response, and the accumulation of H
2
O
2
. Surprisingly,
hcef2
was mapped to a non-sense mutation in the TADA1 (tRNA adenosine deaminase arginine) locus, coding for a plastid targeted tRNA editing enzyme required for efficient codon recognition. Comparison of protein content from representative thylakoid complexes, the cytochrome
bf
complex, and the ATP synthase, suggests that inefficient translation of
hcef2
leads to compromised complex assembly or stability leading to alterations in stoichiometries of major thylakoid complexes as well as their constituent subunits. Altered subunit stoichiometries for photosystem I, ratios and properties of cytochrome
bf
hemes, and the decay kinetics of the flash-induced thylakoid electric field suggest that these defect lead to accumulation of H
2
O
2
in
hcef2
, which we have previously shown leads to activation of NDH-related CEF. We observed similar increases in CEF, as well as increases in H
2
O
2
accumulation, in other translation defective mutants. This suggests that loss of coordination in plastid protein levels lead to imbalances in photosynthetic energy balance that leads to an increase in CEF. These results taken together with a large body of previous observations, support a general model in which processes that lead to imbalances in chloroplast energetics result in the production of H
2
O
2
, which in turn activates CEF. This activation could be from either H
2
O
2
acting as a redox signal, or by a secondary effect from H
2
O
2
inducing a deficit in ATP.
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Details
- Title
- Defects in the Expression of Chloroplast Proteins Leads to H2O2 Accumulation and Activation of Cyclic Electron Flow around Photosystem I
- Creators
- Deserah D Strand - Department of Plant Biology, Michigan State UniversityAaron K Livingston - Institute of Biological Chemistry, Washington State UniversityMio Satoh-Cruz - DOE-Plant Research Laboratory, Michigan State UniversityTyson Koepke - Department of Horticulture, Washington State UniversityHeather M Enlow - Institute of Biological Chemistry, Washington State UniversityNicholas Fisher - DOE-Plant Research Laboratory, Michigan State UniversityJohn E Froehlich - DOE-Plant Research Laboratory, Michigan State UniversityJeffrey A Cruz - DOE-Plant Research Laboratory, Michigan State UniversityDeepika Minhas - Department of Horticulture, Washington State UniversityKim K Hixson - Institute of Biological Chemistry, Washington State UniversityKaori Kohzuma - DOE-Plant Research Laboratory, Michigan State UniversityMary Lipton - Environmental Molecular Sciences Laboratory, Pacific Northwest National LaboratoryAmit Dhingra - Department of Horticulture, Washington State UniversityDavid M Kramer - Department of Plant Biology, Michigan State University
- Publication Details
- Frontiers in plant science, Vol.7, pp.2073-2073
- Academic Unit
- Crop and Soil Sciences, Department of; Horticulture, Department of
- Publisher
- Frontiers Media S.A
- Grant note
- DE-FG02-11ER16220; BES DE-FG02-91ER20021 / U.S. Department of Energy
- Identifiers
- 99900547205901842
- Language
- English
- Resource Type
- Journal article