Complementation of phytochrome chromophore-deficient Arabidopsis by expression of phycocyanobilin:ferredoxin oxidoreductase
| Autor: | Keiko Mukougawa, Takuya Muramoto, Chitose Kami, Akiho Yokota, Takayuki Kohchi, J. Clark Lagarias, Tomoko Shinomura |
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| Rok vydání: | 2004 |
| Předmět: |
chemistry.chemical_classification
Multidisciplinary Base Sequence biology Phytochrome Genetic Complementation Test Mutant Arabidopsis food and beverages Biological Sciences Plants Genetically Modified biology.organism_classification Tetrapyrrole chemistry.chemical_compound chemistry Biochemistry Phycocyanobilin Spectrophotometry Oxidoreductase Etiolation Oxidoreductases Ferredoxin DNA Primers |
| Zdroj: | Proceedings of the National Academy of Sciences. 101:1099-1104 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0307615100 |
| Popis: | The covalently bound phytochromobilin (PϕB) prosthetic group is required for the diverse photoregulatory activities of all members of the phytochrome family in vascular plants, whereas by contrast, green algal and cyanobacterial phytochromes use the more reduced linear tetrapyrrole pigment phycocyanobilin (PCB). To assess the functional consequence of the substitution of PϕB with PCB in plants, the phytochrome chromophore-deficient hy2 mutant of Arabidopsis was transformed with a constitutively expressed pcyA gene that encodes the cyanobacterial enzyme, PCB:ferredoxin oxidoreductase. Spectroscopic analyses of extracts from etiolated seedlings revealed that PcyA expression restored photoactive phytochrome to WT levels, albeit with blue-shifted absorption maxima, while also restoring light lability to phytochrome A. Photobiological measurements indicated that PcyA expression rescued phytochrome-mediated red high-irradiance responses, low-fluence red/far-red (FR) photoreversible responses, and very-low-fluence responses, thus confirming that PCB can functionally substitute for PϕB for these photoregulatory activities. Although PcyA expression failed to rescue phytochrome A-mediated FR high-irradiance responsivity to that of WT, our studies indicate that the FR high-irradiance response is fully functional in pcyA -expressing plants but shifted to shorter wavelengths, indicating that PCB can functionally complement this phytochrome-mediated response in vascular plants. |
| Databáze: | OpenAIRE |
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