Research Repository

Antisense suppression of the small chloroplast protein cp12 in tobacco alters carbon partitioning and severely restricts growth

Howard, TP and Fryer, MJ and Singh, P and Metodiev, M and Lytovchenko, A and Obata, T and Fernie, AR and Kruger, NJ and Quick, WP and Lloyd, JC and Raines, CA (2011) 'Antisense suppression of the small chloroplast protein cp12 in tobacco alters carbon partitioning and severely restricts growth.' Plant Physiology, 157 (2). 620 - 631. ISSN 0032-0889

[img]
Preview
PDF
620.full.pdf - Published Version

Download (870kB) | Preview
[img] Microsoft PowerPoint (PPT Slides of All Figures)
Plant_Physiol.__157(2)_620-31,_Figures.ppt - Supplemental Material

Download (1MB)
[img]
Preview
Image (JPEG) (Supplemental Data - Supplemental Figure 1 )
183806Supp_FigS1_antisense_CP12_Plant_Phys.jpg - Supplemental Material

Download (292kB) | Preview
[img]
Preview
Image (JPEG) (Supplemental Data - Supplemental Figure 2 )
183806Supp_FigS2_antisense_CP12_Plant_Phys.jpg - Supplemental Material

Download (237kB) | Preview
[img]
Preview
Image (JPEG) (Supplemental Data - Supplemental Figure 3 )
183806Supp_FigS3_antisense_CP12_Plant_Phys.jpg - Supplemental Material

Download (181kB) | Preview
[img]
Preview
Image (JPEG) (Supplemental Data - Supplemental Figure 4 )
183806Supp_FigS4_antisense_CP12_Plant_Phys.jpg - Supplemental Material

Download (200kB) | Preview
[img]
Preview
Image (JPEG) (Supplemental Data - Supplemental Figure 5 )
183806Supp_FigS5_antisense_CP12_Plant_Phys.jpg - Supplemental Material

Download (232kB) | Preview

Abstract

The thioredoxin-regulated chloroplast protein CP12 forms a multienzyme complex with the Calvin-Benson cycle enzymes phosphoribulokinase (PRK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). PRK and GAPDH are inactivated when present in this complex, a process shown in vitro to be dependent upon oxidized CP12. The importance of CP12 in vivo in higher plants, however, has not been investigated. Here, antisense suppression of CP12 in tobacco (Nicotiana tabacum) was observed to impact on NAD-induced PRK and GAPDH complex formation but had little effect on enzyme activity. Additionally, only minor changes in photosynthetic carbon fixation were observed. Despite this, antisense plants displayed changes in growth rates and morphology, including dwarfism and reduced apical dominance. The hypothesis that CP12 is essential to separate oxidative pentose phosphate pathway activity from Calvin-Benson cycle activity, as proposed in cyanobacteria, was tested. No evidence was found to support this role in tobacco. Evidence was seen, however, for a restriction to malate valve capacity, with decreases in NADP-malate dehydrogenase activity (but not protein levels) and pyridine nucleotide content. Antisense repression of CP12 also led to significant changes in carbon partitioning, with increased carbon allocation to the cell wall and the organic acids malate and fumarate and decreased allocation to starch and soluble carbohydrates. Severe decreases were also seen in 2-oxoglutarate content, a key indicator of cellular carbon sufficiency. The data presented here indicate that in tobacco, CP12 has a role in redox-mediated regulation of carbon partitioning from the chloroplast and provides strong in vivo evidence that CP12 is required for normal growth and development in plants. © 2011 American Society of Plant Biologists. All Rights Reserved.

Item Type: Article
Subjects: Q Science > Q Science (General)
Q Science > QK Botany
Divisions: Faculty of Science and Health > Biological Sciences, School of
Depositing User: Metodi Metodiev
Date Deposited: 13 Jun 2012 11:05
Last Modified: 22 Jan 2019 22:16
URI: http://repository.essex.ac.uk/id/eprint/2475

Actions (login required)

View Item View Item