NADH-GOGAT Overexpression Does Not Improve Maize (<i>Zea mays</i> L.) Performance Even When Pyramiding with NAD-IDH, GDH and GS
Rafael A. Cañas,
Zhazira Yesbergenova-Cuny,
Léo Belanger,
Jacques Rouster,
Lenaïg Brulé,
Françoise Gilard,
Isabelle Quilleré,
Christophe Sallaud,
Bertrand Hirel
Affiliations
Rafael A. Cañas
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Zhazira Yesbergenova-Cuny
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Léo Belanger
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Jacques Rouster
BIOGEMMA, GM Trait Discovery, Site de la Garenne, Route d’Ennezat, CS 90126, F-63720 Chappes, France
Lenaïg Brulé
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Françoise Gilard
IPS2/Plateforme Métabolisme-Métabolome, Institute of Plant Sciences Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA), Université Paris-Sud, Université Evry, Université Paris-Diderot, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
Isabelle Quilleré
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Christophe Sallaud
BIOGEMMA, GM Trait Discovery, Site de la Garenne, Route d’Ennezat, CS 90126, F-63720 Chappes, France
Bertrand Hirel
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), Centre de Versailles-Grignon, Unité Mixte de Recherche 1318 INRA-AgroParisTech, RD10, 78026 Versailles, CEDEX, France
Maize plants overexpressing NADH-GOGAT were produced in order to determine if boosting 2-Oxoglurate production used as a carbon skeleton for the biosynthesis of amino acids will improve plant biomass and kernel production. The NADH-GOGAT enzyme recycles glutamate and incorporates carbon skeletons into the ammonium assimilation pathway using the organic acid 2-Oxoglutarate as a substrate. Gene pyramiding was then conducted with NAD-IDH and NADH-GDH, two enzymes also involved in the synthesis of 2-Oxoglurate. NADH-GOGAT overexpression was detrimental for shoot biomass production but did not markedly affect kernel yield. Additional NAD-IDH and NADH-GDH activity did not improve plant performance. A decrease in kernel production was observed when NADH-GDH was pyramided to NADH-GOGAT and NAD-IDH. This decrease could not be restored even when additional cytosolic GS activity was present in the plants overexpressing the three enzymes producing 2-Oxoglutarate. Detailed leaf metabolic profiling of the different transgenic plants revealed that the NADH-GOGAT over-expressors were characterized by an accumulation of amino acids derived from glutamate and a decrease in the amount of carbohydrates further used to provide carbon skeletons for its synthesis. The study suggests that 2-Oxoglutarate synthesis is a key element acting at the interface of carbohydrate and amino acid metabolism and that its accumulation induces an imbalance of primary carbon and nitrogen metabolism that is detrimental for maize productivity.