Journal article
An Arabidopsis Mutant with High Cyclic Electron Flow around Photosystem I (hcef) Involving the NADPH Dehydrogenase Complex[W][OA]
The Plant cell, Vol.22(1), pp.221-233
01/2010
Handle:
https://hdl.handle.net/2376/106922
PMCID: PMC2828696
PMID: 20081115
Abstract
Analysis of a mutant,
hcef1
, in chloroplast fructose-1,6-bisphosphatase demonstrates that C
3
plants are capable of high steady state fluxes of cyclic electron flow around photosystem I, which is important for chloroplast energy balance and involves the NAD(P)H dehydrogenase, but not the PGR5, pathway.
Cyclic electron flow (CEFI) has been proposed to balance the chloroplast energy budget, but the pathway, mechanism, and physiological role remain unclear. We isolated a new class of mutant in
Arabidopsis thaliana
,
hcef
for high CEF1, which shows constitutively elevated CEF1. The first of these,
hcef1
, was mapped to chloroplast fructose-1,6-bisphosphatase. Crossing
hcef1
with
pgr5
, which is deficient in the antimycin A–sensitive pathway for plastoquinone reduction, resulted in a double mutant that maintained the high CEF1 phenotype, implying that the PGR5-dependent pathway is not involved. By contrast, crossing
hcef1
with
crr2-2
, deficient in thylakoid NADPH dehydrogenase (NDH) complex, results in a double mutant that is highly light sensitive and lacks elevated CEF1, suggesting that NDH plays a direct role in catalyzing or regulating CEF1. Additionally, the NdhI component of the NDH complex was highly expressed in
hcef1
, whereas other photosynthetic complexes, as well as PGR5, decreased. We propose that (1) NDH is specifically upregulated in
hcef1
, allowing for increased CEF1; (2) the
hcef1
mutation imposes an elevated ATP demand that may trigger CEF1; and (3) alternative mechanisms for augmenting ATP cannot compensate for the loss of CEF1 through NDH.
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Details
- Title
- An Arabidopsis Mutant with High Cyclic Electron Flow around Photosystem I (hcef) Involving the NADPH Dehydrogenase Complex[W][OA]
- Creators
- Aaron K Livingston - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340Jeffrey A Cruz - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340Kaori Kohzuma - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340Amit Dhingra - Horticulture and Landscape Architecture, Washington State University, Pullman, Washington 99164-6340David M Kramer - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
- Publication Details
- The Plant cell, Vol.22(1), pp.221-233
- Academic Unit
- Horticulture, Department of
- Publisher
- American Society of Plant Biologists
- Identifiers
- 99900546963001842
- Language
- English
- Resource Type
- Journal article