Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice
| Autor: | Stephanie Klaus, Ina Horst, Alisdair R. Fernie, Markus Niessen, Stefanie Gaertner, Katrin Krause, Wagner L. Araújo, Norma Staebler, Christoph Peterhänsel, Rashad Kebeish |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
photorespiration
Arabidopsis thaliana Physiology alanine aminotransferase enzymology Glyoxylate cycle plant evolution Arabidopsis Glycine Aminotransferase Oryza sativa Plant Science Dewey Decimal Classification::500 | Naturwissenschaften::580 | Pflanzen (Botanik) Chlorophyta mitochondrion genetics vegetable protein Photosynthesis oxidoreductase Plant Proteins biology Nicotiana tabacum rice article food and beverages carbon dioxide Oryza Alanine Transaminase Peroxisome biology.organism_classification Research Papers Glycolate dehydrogenase glycolic acid Glycolates Mitochondria Chloroplast ddc:580 glycolic acid derivative Biochemistry Photorespiration Embryophyta Oxidoreductases metabolism oxidation reduction reaction Oxidation-Reduction |
| Zdroj: | Journal of Experimental Botany 63 (2012), Nr. 7 Journal of Experimental Botany |
| DOI: | 10.15488/3768 |
| Popis: | The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that link glycolate oxidation to glycine formation are described. By this reaction, the mitochondrial side pathway produces glycine from glyoxylate that can be used in the glycine decarboxylase (GCD) reaction of the major pathway. RNA interference (RNAi) suppression of mitochondrial ALAAT did not result in major changes in metabolite pools under standard conditions or enhanced photorespiratroy flux, respectively. However, RNAi lines showed reduced photorespiratory CO(2) release and a lower CO(2) compensation point. Mitochondria isolated from RNAi lines are incapable of converting glycolate to CO(2), whereas simultaneous overexpression of GlcDH and ALAATs in transiently transformed tobacco leaves enhances glycolate conversion. Furthermore, analyses of rice mitochondria suggest that the side pathway for glycolate oxidation and glycine formation is conserved in monocotyledoneous plants. It is concluded that the photorespiratory pathway from green algae has been functionally conserved in higher plants. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|