Modification of photosynthetic regulation in tomato overexpressing glutathione peroxidase

• Published in: Biochimica et biophysica acta Vol. 1724; no. 1; pp. 108 - 118
• Main Authors: Herbette, Stephane, Menn, Aline Le, Rousselle, Patrick, Ameglio, Thierry, Faltin, Zehava, Branlard, Gérard, Eshdat, Yuval, Julien, Jean-Louis, Drevet, Joël R., Roeckel-Drevet, Patricia
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.06.2005; Elsevier
• Subjects: Animals; Antioxidants - metabolism; Cold Temperature; Electrophoresis, Gel, Two-Dimensional; Gene Expression Regulation, Plant; Glutathione Peroxidase - analysis; Glutathione Peroxidase - genetics; Glutathione Peroxidase - metabolism; Life Sciences; Lycopersicon esculentum - genetics; Mice; Photosynthesis - genetics; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Testicular Hormones - analysis; Testicular Hormones - genetics; Testicular Hormones - metabolism; NPTII; AOS; FBPA-2; F1-6BP; 2-DE; Ran-BP1; GPX
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2005.04.018

To investigate the function of glutathione peroxidase (GPX) in plants, we produced transgenic tomato plants overexpressing an eukaryotic selenium-independent GPX (GPX5). We show here that total GPX activity was increased by 50% in transgenic plants, when compared to control plants transformed with the binary vector without the insert (PZP111). A preliminary two-dimensional electrophoretic protein analysis of the GPX overexpressing plants showed notably a decrease in the accumulation of proteins identified as rubisco small subunit 1 and fructose-1,6-bisphosphate aldolase, two proteins involved in photosynthesis. These observations, together with the fact that in standard culture conditions, GPX-overexpressing plants were not phenotypically distinct from control plants prompted us to challenge the plants with a chilling treatment that is known to affect photosynthesis activity. We found that upon chilling treatment with low light level, photosynthesis was not affected in GPX-overexpressing plants while it was in control plants, as revealed by chlorophyll fluorescence parameters and fructose-1,6-biphosphatase activity. These results suggest that overexpression of a selenium-independent GPX in tomato plants modifies specifically gene expression and leads to modifications of photosynthetic regulation processes.