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Arabidopsis CP12 mutants have reduced levels of phosphoribulokinase and impaired function of the Calvin–Benson cycle

Elena López-Calcagno, Patricia and Omar Abuzaid, Amani and Lawson, Tracy and Anne Raines, Christine (2017) 'Arabidopsis CP12 mutants have reduced levels of phosphoribulokinase and impaired function of the Calvin–Benson cycle.' Journal of Experimental Botany, 68 (9). 2285 - 2298. ISSN 0022-0957

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CP12 is a small, redox-sensitive protein, the most detailed understanding of which is the thioredoxin-mediated regulation of the Calvin–Benson cycle, where it facilitates the formation of a complex between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) in response to changes in light intensity. In most organisms, CP12 proteins are encoded by small multigene families, where the importance of each individual CP12 gene in vivo has not yet been reported. We used Arabidopsis thaliana T-DNA mutants and RNAi transgenic lines with reduced levels of CP12 transcript to determine the relative importance of each of the CP12 genes. We found that single cp12-1, cp12-2, and cp12-3 mutants do not develop a severe photosynthetic or growth phenotype. In contrast, reductions of both CP12-1 and CP12-2 transcripts lead to reductions in photosynthetic capacity and to slower growth and reduced seed yield. No clear phenotype for CP12-3 was evident. Additionally, the levels of PRK protein are reduced in the cp12-1, cp12-1/2, and multiple mutants. Our results suggest that there is functional redundancy between CP12-1 and CP12-2 in Arabidopsis where these proteins have a role in determining the level of PRK in mature leaves and hence photosynthetic capacity.

Item Type: Article
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Science and Health > Life Sciences, School of
Depositing User: Jim Jamieson
Date Deposited: 02 May 2017 14:29
Last Modified: 14 Oct 2019 18:17

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