Details
| Original language | English |
|---|---|
| Pages (from-to) | 557-65 |
| Number of pages | 9 |
| Journal | Physiologia plantarum |
| Volume | 133 |
| Issue number | 3 |
| Publication status | Published - Jul 2008 |
Abstract
Persistent light quality gradients in dense plant populations induce imbalances in the distribution of excitation energy between the photosystems. Plants counteract such conditions by re-adjusting the stoichiometry of photosystems, which involves control of photosynthesis gene expression both in chloroplasts and in the nucleus. Decisive control parameters are redox signals from the photosynthetic electron transport chain, one prominent is the plastoquinone (PQ) pool. In a recent study, a plastocyanin (PC)-promoter::beta-glucuronidase reporter gene construct in tobacco demonstrated reversible redox regulation in response to varying light qualities. Here, northern and Western analyses demonstrate that this promoter regulation also accounts for the accumulation of the endogenous tobacco PetE gene transcripts and the protein amounts of the encoded PC. Hence, the reporter gene construct reflects the natural regulation of this nuclear gene in tobacco. In kinetic experiments, the response of the construct to either oxidation or reduction of the PQ pool was tested by defined light quality shifts. The construct displayed upregulation in response to a reduction signal and downregulation in response to an oxidation signal, both with a half-time of about 24 h. The response was finished after 48 h. DCMU application abolished the upregulation in response to the reduction signal, indicating the dependence on thylakoid membrane electron transport. To study the redox-responsive promoter region in more detail, several promoter deletion constructs were tested for their responsiveness. All constructs displayed a reversible response to light-induced oxidation and reduction signals; however, a minimal promoter region localised between -168 to -79 bp upstream of the transcription start site was sufficient to confer this redox regulation. This indicates that photosynthetic redox signals act on distinct regions in the PC promoter in a manner independent from photoreceptors and upstream cis elements conferring high basic expression in the light.
Keywords
- Base Sequence, Blotting, Northern, Blotting, Western, Diuron/pharmacology, Gene Expression Regulation, Plant/drug effects, Glucuronidase/genetics, Kinetics, Models, Genetic, Molecular Sequence Data, Oxidation-Reduction/drug effects, Photosynthesis/genetics, Plant Proteins/genetics, Plants, Genetically Modified, Plastocyanin/genetics, Promoter Regions, Genetic/genetics, Tobacco/genetics
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In: Physiologia plantarum, Vol. 133, No. 3, 07.2008, p. 557-65.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Photosynthetic redox regulation of the plastocyanin promoter in tobacco
AU - Schütze, Katia
AU - Steiner, Sebastian
AU - Pfannschmidt, Thomas
PY - 2008/7
Y1 - 2008/7
N2 - Persistent light quality gradients in dense plant populations induce imbalances in the distribution of excitation energy between the photosystems. Plants counteract such conditions by re-adjusting the stoichiometry of photosystems, which involves control of photosynthesis gene expression both in chloroplasts and in the nucleus. Decisive control parameters are redox signals from the photosynthetic electron transport chain, one prominent is the plastoquinone (PQ) pool. In a recent study, a plastocyanin (PC)-promoter::beta-glucuronidase reporter gene construct in tobacco demonstrated reversible redox regulation in response to varying light qualities. Here, northern and Western analyses demonstrate that this promoter regulation also accounts for the accumulation of the endogenous tobacco PetE gene transcripts and the protein amounts of the encoded PC. Hence, the reporter gene construct reflects the natural regulation of this nuclear gene in tobacco. In kinetic experiments, the response of the construct to either oxidation or reduction of the PQ pool was tested by defined light quality shifts. The construct displayed upregulation in response to a reduction signal and downregulation in response to an oxidation signal, both with a half-time of about 24 h. The response was finished after 48 h. DCMU application abolished the upregulation in response to the reduction signal, indicating the dependence on thylakoid membrane electron transport. To study the redox-responsive promoter region in more detail, several promoter deletion constructs were tested for their responsiveness. All constructs displayed a reversible response to light-induced oxidation and reduction signals; however, a minimal promoter region localised between -168 to -79 bp upstream of the transcription start site was sufficient to confer this redox regulation. This indicates that photosynthetic redox signals act on distinct regions in the PC promoter in a manner independent from photoreceptors and upstream cis elements conferring high basic expression in the light.
AB - Persistent light quality gradients in dense plant populations induce imbalances in the distribution of excitation energy between the photosystems. Plants counteract such conditions by re-adjusting the stoichiometry of photosystems, which involves control of photosynthesis gene expression both in chloroplasts and in the nucleus. Decisive control parameters are redox signals from the photosynthetic electron transport chain, one prominent is the plastoquinone (PQ) pool. In a recent study, a plastocyanin (PC)-promoter::beta-glucuronidase reporter gene construct in tobacco demonstrated reversible redox regulation in response to varying light qualities. Here, northern and Western analyses demonstrate that this promoter regulation also accounts for the accumulation of the endogenous tobacco PetE gene transcripts and the protein amounts of the encoded PC. Hence, the reporter gene construct reflects the natural regulation of this nuclear gene in tobacco. In kinetic experiments, the response of the construct to either oxidation or reduction of the PQ pool was tested by defined light quality shifts. The construct displayed upregulation in response to a reduction signal and downregulation in response to an oxidation signal, both with a half-time of about 24 h. The response was finished after 48 h. DCMU application abolished the upregulation in response to the reduction signal, indicating the dependence on thylakoid membrane electron transport. To study the redox-responsive promoter region in more detail, several promoter deletion constructs were tested for their responsiveness. All constructs displayed a reversible response to light-induced oxidation and reduction signals; however, a minimal promoter region localised between -168 to -79 bp upstream of the transcription start site was sufficient to confer this redox regulation. This indicates that photosynthetic redox signals act on distinct regions in the PC promoter in a manner independent from photoreceptors and upstream cis elements conferring high basic expression in the light.
KW - Base Sequence
KW - Blotting, Northern
KW - Blotting, Western
KW - Diuron/pharmacology
KW - Gene Expression Regulation, Plant/drug effects
KW - Glucuronidase/genetics
KW - Kinetics
KW - Models, Genetic
KW - Molecular Sequence Data
KW - Oxidation-Reduction/drug effects
KW - Photosynthesis/genetics
KW - Plant Proteins/genetics
KW - Plants, Genetically Modified
KW - Plastocyanin/genetics
KW - Promoter Regions, Genetic/genetics
KW - Tobacco/genetics
U2 - 10.1111/j.1399-3054.2008.01118.x
DO - 10.1111/j.1399-3054.2008.01118.x
M3 - Article
C2 - 18419738
VL - 133
SP - 557
EP - 565
JO - Physiologia plantarum
JF - Physiologia plantarum
SN - 0031-9317
IS - 3
ER -