The Role of Phosphoenolpyruvate Carboxylase-Protein Kinase in C4 Photosynthesis: Insights from Zea mays Mutant Analysis
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Le résumé fourni par la source
Understanding the regulation of enzyme activity involved in photosynthesis is essential for engineering enhanced carbon fixation in crops. In C4 plants, the enzyme phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) is one of the most abundant leaf enzymes and plays an essential role in photosynthetic carbon dioxide (CO2) fixation. The enzyme also plays a key role in central metabolism (e.g., providing intermediates to the citric acid cycle) and therefore must be highly regulated to coordinate its activity. The regulation of PEPC activity can occur allosterically by glucose 6-phosphate activation and malate inhibition, which is in part influenced by reversible phosphorylation. A specific light-dependent phosphorylation of PEPC at an N-terminal serine residue by the PEPC-protein kinase (PEPC-PK) can regulate its sensitivity to this allosteric regulation. However, the impact of this PEPC phosphorylation has not been tested in a C4 crop. Therefore, we created PEPC-PK mutant lines in Zea mays to assess the impact of PEPC phosphorylation on its allosteric regulation, photosynthesis, and growth. While the maximum PEPC activity was unchanged, PEPC in the PEPC-PK mutant plants was not phosphorylated under light and was more sensitive to malate inhibition. However, gas exchange, electron transport, and field biomass analyses showed no differences in the PEPC-PK mutant plants. These results demonstrate that in Z. mays PEPC phosphorylation affects enzyme sensitivity to malate in vitro but does not substantially alter photosynthetic performance or growth under field conditions suggesting additional regulation of PEPC activity in planta.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé, mais le titre doit être comparé manuellement.
- Titre Crossref
- The Role of Phosphoenolpyruvate Carboxylase-Protein Kinase in C4 Photosynthesis: Insights from <i>Zea mays</i> Mutant Analysis
- Date Crossref
- 20/08/2026
- Éditeur
- Oxford University Press (OUP)
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Washington State University pays non établi dans la noticeUniversité ou école supérieure
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University of Illinois Urbana-Champaign Department of Crop Sciences pays non établi dans la noticeUniversité ou école supérieure
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Monash University pays non établi dans la noticeUniversité ou école supérieure
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Australian National University pays non établi dans la noticeUniversité ou école supérieure
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School of Biological Sciences pays non établi dans la noticeUniversité ou école supérieure
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Research School of Biology Division of Plant Science pays non établi dans la noticeUniversité ou école supérieure
Washington State University, Department of Crop Sciences — University of Illinois Urbana-Champaign et Monash University, avec 3 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.