Hydrogen Peroxide Mediates the Induction of Chloroplastic Ndh Complex under Photooxidative Stress in Barley

Casano, Leonardo M.; Martı́n, Mercedes; Sabater, Bartolomé

doi:10.1104/pp.125.3.1450

Cited by 122 publications

(97 citation statements)

References 30 publications

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“…These results imply that H 2 O 2 -induced CEF does not involve the PGR5/PGRL1 pathway (4, 6, 7) but favors the involvement of the chloroplast NDH complex, as previously shown in hcef1 (37). Consistent with this view, accumulation and phosphorylation of the NDH complex has been associated with increased activity in the presence of oxidative stress (27,29), and its activation results in increased postillumination fluorescence rise, which was increased in the GO5 mutant (Fig. S6). A Regulatory Role for H 2 O 2 in Activation of CEF?…”

Section: Effects Of H 2 O 2 Production By Plants Expressing Glycolatesupporting

confidence: 67%

“…3), to involve de novo protein synthesis, which is expected to be considerably slower (60,61), suggesting that short-term H 2 O 2 production can activate preexisting CEF machinery, consistent with a mechanism for rapid activation of CEF to meet fluctuating ATP demands, as proposed earlier (27). In addition, H 2 O 2 was shown in previous studies (29) as well as in this work (Fig. S8) to induce higher levels of NDH proteins, suggesting a dual mode of action both at the enzyme and expression levels.…”

Section: Effects Of H 2 O 2 Production By Plants Expressing Glycolatementioning

confidence: 49%

“…Based on in vitro studies, it was previously proposed that H 2 O 2 could activate CEF or chlororespiration by modifying the NDH complex (27). It has also been shown that H 2 O 2 can increase the expression of the NDH complex (29) and may further affect the accumulation of photosynthetic metabolites, indirectly activating CEF (26). Consistent with this possibility, H 2 O 2 is a well-documented signaling molecule (33), possibly through its ability to oxidize thiols (34,35).…”

Section: Significancementioning

confidence: 54%

“…Other possible regulatory mechanisms include sensing of ATP/ADP ratios (23,24), the redox status of NAD(P)H or Fd (25), various CBB metabolic intermediates (reviewed in ref. 26), calcium signaling (15,27), phosphorylation of CEF-related proteins (27), and the reactive oxygen species H 2 O 2 (26)(27)(28)(29).…”

mentioning

confidence: 99%

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Activation of cyclic electron flow by hydrogen peroxide in vivo

Strand

Livingston

Satoh-Cruz

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

124

116

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Cyclic electron flow (CEF) around photosystem I is thought to balance the ATP/NADPH energy budget of photosynthesis, requiring that its rate be finely regulated. The mechanisms of this regulation are not well understood. We observed that mutants that exhibited constitutively high rates of CEF also showed elevated production of H 2 O 2 . We thus tested the hypothesis that CEF can be activated by H 2 O 2 in vivo. CEF was strongly increased by H 2 O 2 both by infiltration or in situ production by chloroplastlocalized glycolate oxidase, implying that H 2 O 2 can activate CEF either directly by redox modulation of key enzymes, or indirectly by affecting other photosynthetic processes. CEF appeared with a half time of about 20 min after exposure to H 2 O 2 , suggesting activation of previously expressed CEF-related machinery. H 2 O 2 -dependent CEF was not sensitive to antimycin A or loss of PGR5, indicating that increased CEF probably does not involve the PGR5-PGRL1 associated pathway. In contrast, the rise in CEF was not observed in a mutant deficient in the chloroplast NADPH:PQ reductase (NDH), supporting the involvement of this complex in CEF activated by H 2 O 2 . We propose that H 2 O 2 is a missing link between environmental stress, metabolism, and redox regulation of CEF in higher plants. I n oxygenic photosynthesis, linear electron flow (LEF) is the process by which light energy is captured to drive the extraction of electrons and protons from water and transfer them through a system of electron carriers to reduce NADPH. LEF is coupled to proton translocation into the thylakoid lumen, generating an electrochemical gradient of protons ðΔμ H +Þ or proton motive force (pmf). The pmf drives the synthesis of ATP to power the reactions of the Calvin-Benson-Bassham (CBB) cycle and other essential metabolic processes in the chloroplast. The pmf is also a key regulator of photosynthesis in that it activates the photoprotective q E response to dissipate excess light energy and downregulates electron transfer by controlling the rate of oxidation of plastoquinol at the cytochrome b 6 f complex (b 6 f), thus preventing the buildup of reduced intermediates (1, 2).LEF results in the transfer or deposition into the lumen of three protons for each electron transferred through PSII, plastoquinone (PQ), b 6 f, plastocyanin, and photosystem I (PSI) to ferredoxin (Fd). The synthesis of one ATP is thought to require the passage of 4.67 protons through the ATP synthase, so that LEF should produce a ratio of ATP/NADPH of about 1.33; this ratio is too low to sustain the CBB cycle or supply ATP required for translation, protein transport, or other ATP-dependent processes (3). In addition, the relative demands for ATP and NADPH can change dramatically depending on environmental, developmental, and other factors, leading to rapid energy imbalances that require dynamical regulation of ATP/NADPH balance.Several alternative electron flow pathways in the chloroplast have been proposed to augment ATP production, thus balancing the ATP/NADPH ...

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Section: Effects Of H 2 O 2 Production By Plants Expressing Glycolatesupporting

confidence: 67%

Section: Effects Of H 2 O 2 Production By Plants Expressing Glycolatementioning

confidence: 49%

Section: Significancementioning

confidence: 54%

mentioning

confidence: 99%

See 2 more Smart Citations

Activation of cyclic electron flow by hydrogen peroxide in vivo

Strand

Livingston

Satoh-Cruz

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

124

116

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“…They might function as protective agents against reactive oxygen species . Hydrogen peroxides, for instance, can stimulate transcription of plastid ndh genes under photooxidative stress (Casano et al, 2001). We also identified two PFKs in the TAC, one of them was also found in sRNAP preparations (Suzuki et al, 2004).…”

Section: Discussionmentioning

confidence: 75%

pTAC2, -6, and -12 Are Components of the Transcriptionally Active Plastid Chromosome That Are Required for Plastid Gene Expression

et al. 2005

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Transcription in plastids is mediated by a plastid-encoded multimeric (PEP) and a nuclear-encoded single-subunit RNA polymerase (NEP) and a still unknown number of nuclear-encoded factors. By combining gel filtration and affinity chromatography purification steps, we isolated transcriptionally active chromosomes from Arabidopsis thaliana and mustard (Sinapis alba) chloroplasts and identified 35 components by electrospray ionization ion trap tandem mass spectrometry. Eighteen components, called plastid transcriptionally active chromosome proteins (pTACs), have not yet been described. T-DNA insertions in three corresponding genes, ptac2, -6, and -12, are lethal without exogenous carbon sources. Expression patterns of the plastid-encoded genes in the corresponding knockout lines resemble those of Drpo mutants. For instance, expression of plastid genes with PEP promoters is downregulated, while expression of genes with NEP promoters is either not affected or upregulated in the mutants. All three components might also be involved in posttranscriptional processes, such as RNA processing and/or mRNA stability. Thus, pTAC2, -6, and -12 are clearly involved in plastid gene expression.

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Transcription of Plastid Genes

Liere¹,

Börner²

Regulation of Transcription in Plants

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Hydrogen Peroxide Mediates the Induction of Chloroplastic Ndh Complex under Photooxidative Stress in Barley

Cited by 122 publications

References 30 publications

Activation of cyclic electron flow by hydrogen peroxide in vivo

Activation of cyclic electron flow by hydrogen peroxide in vivo

pTAC2, -6, and -12 Are Components of the Transcriptionally Active Plastid Chromosome That Are Required for Plastid Gene Expression

Transcription of Plastid Genes

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