Over-expression of phenol-oxidising peroxidases alters the UV-susceptibility of transgenic Nicotiana tabacum
| Autor: | Folke Sitbon, Philip J. Dix, Laura Heggie, Malin Elfstrand, Marcel A. K. Jansen, Roger N. F. Thorneley |
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| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
biology Physiology Nicotiana tabacum food and beverages Plant Science Oxidative phosphorylation biology.organism_classification Isozyme chemistry.chemical_compound Enzyme chemistry Biochemistry Photoprotection biology.protein Phenols Chlorophyll fluorescence Peroxidase |
| Zdroj: | The New phytologistReferences. 163(3) |
| ISSN: | 1469-8137 |
| Popis: | Summary • Class III peroxidases catalyse the oxidative crosslinking of UV-absorbing phenolics. The effect of changes in the activity of phenol oxidising peroxidases (EC 1.11.1.7) on UV-tolerance in Nicotiana tabacum plants has been determined. • The UV-sensitivity of transgenic N. tabacum lines, altered in their peroxidase expression pattern, was studied by measuring radiation effects on photosynthetic efficiency. • Analysis of the effect of UV-radiation on the relative variable chlorophyll fluorescence showed that the SPI-2 line, which over-expresses a defence-related cationic peroxidase, is markedly UV-tolerant. By contrast, the ROPN3-line, which overexpresses a synthetic horseradish peroxidase-C gene, was found to be UV-sensitive. The increased activity of indole-3-acetic acid (IAA) inducible peroxidases in homozygous IAA-overproducing transgenic plants was also found to correlate with UV-sensitivity. • It is concluded that only specific peroxidase isozymes, through their effects on phenolic metabolism, contribute to the UV protection response. Thus, the analysis of the role of isozymes in UV-protection addresses fundamental questions of isozyme diversity and/or redundancy in relation to phenolic substrates. |
| Databáze: | OpenAIRE |
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