V. Leveau, J. Lorgeou, and J. L. Prioul, Maize in the world economy: a challenge for scientific research-how to produce more cheaper, Advances in Maize, vol.3, pp.509-534, 2011.

W. R. Raun and G. V. Johnson, Improving nitrogen use efficiency for cereal production, Agron J, vol.91, pp.357-363, 1999.

D. E. Edmonds, B. S. Tubaña, J. P. Kelly, J. L. Crain, M. D. Edmonds et al., Maize grain yield response to variable row nitrogen fertilization, J Plant Nutr, vol.36, pp.1013-1024, 2013.

B. Hirel, L. Gouis, J. Ney, B. Gallais, and A. , The challenge of improving nitrogen use efficiency in crop plants: towards a more central role for genetic variability and quantitative genetics within integrated approaches, J Exp Bot, vol.58, pp.2369-2387, 2007.

B. Hirel, T. Tétu, P. J. Lea, and F. Dubois, Improving nitrogen use efficiency in crops for a sustainable agriculture, Sustainability, vol.3, pp.1452-1485, 2011.

C. H. Mcallister, P. H. Beatty, and A. G. Good, Engineering nitrogen use efficient crop plants: the current status, Plant Biotech J, vol.10, pp.1011-1025, 2012.

B. Hirel and A. Gallais, Nitrogen use efficiency. Physiological, molecular and genetic investigations towards crop improvement, Advances in Maize, vol.3, pp.285-310, 2011.
URL : https://hal.archives-ouvertes.fr/hal-01203981

B. Hirel, A. Martin, T. Tercé-laforgue, M. B. Gonzalez-moro, and J. M. Estavillo, Physiology of maize I: A comprehensive and integrated view of nitrogen metabolism in a C4 plant, Physiol Plant, vol.124, pp.167-177, 2005.

Z. Ding, S. Weissmann, M. Wang, B. Du, L. Huang et al., Identification of photosynthesis-associated C4 candidate genes through comparative leaf gradient transcriptome in multiple lineages of C3 and C4 species, PLoS ONE 10: e0140629, 2015.

C. W. Bacon and D. M. Hinton, Bacterial endophytes: the endophytic niche, its occupants, and its utility, pp.155-194, 2006.

S. Complant, C. Clément, and A. Sessitch, Plant growth-promoting bacteria in the rhizo-and endosphere of plants: their role, colonization, mechanisms involved and prospects for utilization, Soil Biol Biochem, vol.42, pp.669-678, 2010.

K. B. Kuan, R. Othman, K. A. Rahim, and Z. H. Shamsuddin, Plant growth-promoting rhizobacteria inoculation to enhance vegetative growth, nitrogen fixation and nitrogen remobilisation of maize under greenhouse conditions, PLoS ONE, vol.11, 2016.

M. Simons, R. Saha, N. Amiour, A. Kumar, L. Guillard et al., Assessing the metabolic impact of nitrogen availability using a compartmentalized maize leaf genome-scale model, Plant Physiol, vol.166, pp.1659-1674, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01563730

A. G. Good, A. K. Shrawat, and D. G. Muench, Can less yield more? Is reducing nutrient input into the environment compatible with maintaining crop production?, Trends Plant Sci, vol.9, pp.597-605, 2004.

A. G. Good and P. H. Beatty, Biotechnological approaches to improving nitrogen use efficiency in plants: Alanine aminotransferase as a case study, pp.165-191, 2011.

Y. Y. Liu, L. H. Wu, J. A. Baddeley, and C. A. Watson, Models of biological nitrogen fixation of legumes. A review, Agron Sustain Dev, vol.31, pp.155-172, 2011.
URL : https://hal.archives-ouvertes.fr/hal-00930470

G. Gupta, J. Panwar, S. Akhtar, M. Jha, and P. N. , Endophytic nitrogen-fixing bacteria as biofertilizer, pp.183-221, 2012.

A. Tkacz and P. Poole, Role of root microbiota in plant productivity, J Exp Bot, vol.66, pp.2167-2175, 2015.

R. De-souza, A. Ambrosini, and L. Passaglia, Plant growth-promoting bacteria as inoculants in agricultural soils, Genet Mol Biol, vol.38, pp.401-419, 2015.

A. Montañez and M. Sicardi, Effects of inoculation on growth promotion and biological nitrogen fixation in maize (Zea mays L.) under greenhouse and field conditions, Bas Res J Agric Sci Rev, vol.2, pp.102-110, 2013.

L. Roesch, L. Passaglia, F. M. Bento, E. W. Triplett, and F. Camargo, Diversity of diazotrophic endophytic bacteria associated with maize plants. Rev Bras Ciência Solo, vol.31, pp.1367-1380, 2007.

L. Roesch, F. O. Camargo, F. Bento, and E. Triplett, Biodiversity of diazotrophic bacteria within the soil, root and stem of field-grown maize, Plant Soil, vol.302, pp.91-104, 2008.

D. Johnston-monje and M. N. Raizada, Conservation and diversity of seed associated endophytes in Zea across boundaries of evolution, ethnography and ecology, PLoS ONE, vol.6, 2011.

A. Montañez, A. R. Blanco, C. Barlocco, M. Beracochea, and M. Sicardi, Characterization of cultivable putative endophytic plant growth promoting bacteria associated with maize cultivars (Zea mays L.) and their inoculation effects in vitro, Appl Soil Ecol, vol.58, pp.21-28, 2012.

A. C. Ikeda, L. L. Bassani, D. Adamoski, D. Stringari, V. K. Cordeiro et al., Morphological and genetic characterization of endophytic bacteria isolated from roots of different maize genotypes, Microb Ecol, vol.65, p.22956211, 2013.

D. Johnston-monje, W. K. Mousa, G. Lazarovits, and M. N. Raizada, Impact of swapping soils on the endophytic bacterial communities of pre-domesticated, ancient and modern maize, BMC Plant Biol, vol.14, p.25227492, 2014.

C. Santi, D. Bogusz, and C. Franche, Biological nitrogen fixation in non-legume plants, Ann Bot, vol.111, pp.743-767, 2013.

B. Hirel, P. Lea, and . Springer, Ammonia assimilation, pp.79-99, 2001.

I. E. García-de-salamone, J. Döbereiner, S. Urquiaga, and R. M. Boddey, Biological nitrogen fixation in Azospirillum strain-maize genotype associations as evaluated by the 15 N isotope dilution technique, Biol Fertil Soils, vol.23, pp.249-256, 1996.

A. Montañez, C. Abreu, P. Gill, G. Hardarson, and M. Sicardi, Biological nitrogen fixation in maize (Zea mays L.) by 15 N isotope-dilution and identification of associated culturable diazotrophs, Biol Fertil Soils, vol.45, pp.253-263, 2009.

V. Pankievicz, F. P. Amaral, K. Santos, B. Agtuca, Y. Xu et al., Robust biological nitrogen fixation in a model grass-bacterial association, Plant J, vol.81, pp.907-926, 2015.

I. E. García-de-salamone and J. Döbereiner, Maize genotypes effects on the response to Azospirillum inoculation, Biol Fertil Soils, vol.21, pp.193-196, 1996.

S. C. Wu, Z. H. Cao, Z. G. Li, K. C. Cheung, and M. H. Wong, Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: a greenhouse trial, Geoderma, vol.125, pp.155-166, 2005.

M. Hungria, R. J. Campo, E. M. Souza, and F. O. Pedrosa, Inoculation with selected strains of Azospirillum brasilense and A. lipoferum improves yields of maize and wheat in Brazil, Plant Soil, vol.331, pp.413-425, 2010.

S. Mehnaz, T. Kowalik, B. Reynolds, and G. Lazarovits, Growth promoting effects of corn (Zea mays) bacterial isolates under greenhouse and field conditions, Soil Biol Biochem, vol.42, pp.1848-1856, 2010.

F. Perez-montano, C. Alias-villegas, R. A. Bellogin, P. Del-cerro, M. R. Espuny et al., Plant growth promotion in cereal and leguminous agricultural important plants: From microorganism capacities to crop production, Microbiol Res, vol.169, pp.325-336, 2014.

M. Hubbard, J. J. Germida, and V. Vujanovic, Fungal endophytes enhance wheat heat and drought tolerance in terms of grain yield and second-generation seed viability, J Appl Microbiol, vol.116, pp.109-122, 2014.

E. De-matos-nogueira, F. Vinagre, H. P. Masuda, C. Vargas, V. L. Muniz-de-pádua et al., Expression of sugarcane genes induced by inoculation with Gluconacetobacter diazotrophicus and Herbaspirillum rubrisubalbicans, Genet Mol Biol, vol.24, pp.199-206, 2001.

F. R. Rocha, F. S. Papini-terzi, M. Y. Nishiyama, . Jr, R. Vêncio et al., Signal transduction-related responses to phytohormones and environmental challenges in sugarcane, BMC Genomics, vol.8, p.71, 2007.

D. Alberton, M. Müller-santos, L. C. Brusamarello-santos, G. Valdameri, F. A. Cordeiro et al., Comparative proteomics analysis of the rice roots colonized by Herbaspirillum seropedicae strain SmR1 reveals induction of the methionine recycling in the plant host, J Proteome Res, vol.12, pp.4757-4768, 2013.

F. Plucani-do-amaral, V. Bueno, J. , S. Hermes, V. et al., Gene expression analysis of maize seedlings (DKB240 variety) inoculated with plant growth promoting bacterium Herbaspirillum seropedicae, Symbiosis, vol.62, pp.41-50, 2014.

S. Ferrari, C. , P. Amaral, F. , C. Bueno et al., Expressed proteins of Herbaspirillum seropedicae in maize (DBK240) roots bacteria interaction revealed using proteomics

, Appl Biochem Biotechnol, vol.174, pp.2267-2277, 2014.

F. Thiebaut, C. A. Rojas, C. Grativol, R. Motta, M. Vieira et al., Genome-wide identification of microRNA and siRNA responsive to endophytic beneficial diazotrophic bacteria in maize, BMC Genomics, vol.15, p.766, 2014.

L. Roncato-maccari, H. Ramos, F. O. Pedrosa, Y. Alquini, L. S. Chubastsu et al., Endophytic Herbaspririllum seropediacae expresses nif genes in gramineous plants, FEMS Microbiol Lett, vol.45, pp.39-47, 2003.

A. C. Faleiro, T. P. Pereira, E. Espindula, and F. Brod, Maisonnave Arisa AC. Real time PCR detection targeting nifA gene of plant growth promoting bacteria Azospirillum brasilense strain FP2 in maize roots, Symbiosis, vol.61, pp.125-133, 2013.

E. M. Souza, F. O. Pedrosa, L. U. Rigo, H. B. Machado, and M. G. Yates, Expression of the nifA gene of Herbaspirillum deropedicae: role of the NtrC and NifA binding sites and for the -24/-12 promoter element, Microbiology, vol.146, pp.1407-1418, 2000.

F. O. Pedrosa and M. G. Yates, Regulation of nitrogen fixation (nif) genes of Azospirillum brasilense by nifA and ntrC (gln) type gene products, FEMS Microbiol Lett, vol.23, pp.95-101, 1984.

G. Klassen, F. O. Pedrosa, E. M. De-souza, S. Funayama, and L. Rigo, Effect of nitrogen compounds on nitrogenase activity in Herbaspirillum seropedicae, Can J Microbiol, vol.43, pp.887-891, 1997.

H. B. Machado, S. Funayama, L. U. Rigo, and F. O. Pedrosa, Excretion of ammonium by Azospirillum brasilense mutants resistant to ethylenediamine, Can J Microbiol, vol.37, pp.549-553, 1991.

L. Camus-kulandaivelu, J. B. Veyrieras, D. Madur, V. Combes, M. Fourman et al., Maize adaptation to temperate climate: relationship between population structure and polymorphism in the Dwarf8 gene, Genetics, vol.172, pp.2449-2469, 2006.

D. Hoagland and D. Arnon, In California Agriculture Experimental Station Circular, California; College of Agriculture, Circular, vol.37, 1950.

F. Berrabah, M. Bourcy, A. Cayrel, A. Eschstruth, and S. Mondy, Growth Conditions Determine the DNF2 Requirement for Symbiosis, PLoS ONE, vol.9, 2014.
URL : https://hal.archives-ouvertes.fr/hal-02410365

O. Fiehn, Metabolite profiling in Arabidopsis, Molecular Biology. Arabidopsis Protocols, pp.439-447, 2006.

G. Tcherkez, A. Mahé, P. Gauthier, C. Mauve, and E. Gout, In folio respiratory fluxomics revealed by 13 C isotopic labeling and H/D isotope effects highlight the noncyclic nature of the tricarboxylic acid "cycle" in illuminated leaves, Plant Physiol, vol.151, pp.620-630, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00448349

W. Weckwerth, K. Wendel, and O. Fienh, Process for the integrated extraction, identification and quantification of metabolites, proteins and RNA to reveal their co-regulation in biological networks, Proteomics, vol.4, pp.78-83, 2004.

J. Mercier and S. E. Lindow, Role of Leaf Surface Sugars in Colonization of Plants by Bacterial Epiphytes, Appl Environ Microbiol, vol.66, pp.369-374, 2000.

A. Gallais and B. Hirel, An approach of the genetics of nitrogen use efficiency in in maize, J Exp Bot, vol.396, pp.295-306, 2004.

R. A. Monteiro, E. Balsanelli, R. Wassem, A. Marin, L. C. Brusamarello-santos et al., Herbaspirillum-plant interaction: microscopical, histological and molecular aspects, Plant Soil, vol.356, pp.175-196, 2012.

L. Pereg, L. E. De-bashan, and Y. Bashna, Assessment of affinity and specificity of Azospirillum for plants, Plant Soil, vol.399, pp.389-414, 2005.

E. C. Cocking, Endophytic colonization of plant roots by nitrogen-fixing bacteria, Plant Soil, vol.252, pp.169-175, 2003.

J. I. Baldani, V. M. Reis, V. Baldani, and J. Döbereiner, Review: a brief history of nitrogen fixation in sugarcane-reasons for success in Brasil, Func Plant Biol, vol.29, pp.417-423, 2002.

V. M. Reis, J. I. Baldani, D. Baldani, V. L. Döbereiner, and J. , Biological nitrogen fixation in graminae and palm trees, Critic Rev Plant Sci, vol.19, pp.227-247, 2000.

C. Alves, G. , S. Videira, S. Urquiaga, S. et al., Differential plant growth promotion and nitrogen fixation in two genotypes of maize by several Herbaspirillum inoculants, Plant Soil, vol.387, pp.307-321, 2015.

. Rodríguez-blanco, M. Sicardi, and L. Frioni, Plant genotype and nitrogen fertlization effects on abundance and diversity of diazotrophic bacteria associated with maize (Zea mays L.), Biol Fertil Soils, vol.51, pp.391-402, 2015.

M. Ahemad and M. Kibret, Mechanisms and application of plant growth promoting rhizobacteria: current perspective, J King Saud Univ, vol.26, pp.1-20, 2014.

G. Brader, S. Compant, B. Mitter, F. Trognitz, and A. Sessitch, Metabolic potential of endophytic bacteria, Curr Opin Plant Biol, vol.27, pp.30-37, 2014.

T. Carvalho, E. Balsemão-pires, R. M. Saraiva, P. Ferreira, and A. S. Hermerly, Nitrogen signalling in plant interactions with associative and endophytic diazotrophic bacteria, J Exp Bot, vol.65, pp.5631-5642, 2014.

T. L. Carvalho, H. G. Ballesteros, F. Thiebaut, P. C. Ferreira, and A. S. Hemerly, Nice to meet you: genetic, epigenetic and metabolic controls of plant perception of beneficial associative and endophytic diazotrophic bacteria in non-leguminous plants, Plant Mol. Biol, vol.90, p.26821805, 2016.

J. Vacheron, G. Desbrosses, M. L. Bouffaud, B. Touraine, Y. Moënne-loccoz et al., Plant growthpromoting rhizobacteria and roots system functioning, Front Plant Sci, vol.4, p.356, 2013.

N. O. Aguiar, L. O. Medici, F. L. Olivares, L. B. Dobbss, A. Torres-netto et al., Metabolic profile and antioxidant responses during drought stress recovery in sugarcane treated with humic acids and endophytic diazotrophic bacteria, Ann Appl Biol, vol.168, pp.203-213, 2016.

J. E. Lunn, I. Delorge, C. M. Figueroa, P. Van-dijck, and M. Stitt, Trehalose metabolism in plants, Plant J, vol.79, pp.544-567, 2014.

T. K. Patel and J. D. Williamson, Mannitol in plants, fungi, and Plant-Fungal interactions, Trends Plant Sci, vol.21, pp.486-497, 2016.

U. Haq, I. Zhang, M. Yang, P. Van-elsas, and D. , The interaction of bacteria with fungi in soil: emerging concepts, Adv Appl Microbiol, vol.89, p.25131403, 2014.

H. Weiner, S. Blechschmidt-schenider, H. Mohme, W. Eschrich, and H. W. Heldt, Phloem transport of amino acids. Comparison of amino acid contents of maize leaves and of sieve tube exudate, Plant Physiol Biochem, vol.29, pp.19-23, 1991.

A. Martin, J. Lee, T. Kichey, D. Gerentes, M. Zivy et al., Two cytosolic glutamine synthetase isoforms of maize are specifically involved in the control of grain production, Plant Cell, vol.18, pp.3252-3274, 2006.
URL : https://hal.archives-ouvertes.fr/hal-01927336

Z. Yesbergenova-cuny, S. Dinant, M. L. Martin-magniette, I. Quillere, P. Armengaud et al., Genetic variability of the phloem sap metabolite content of maize (Zea mays L.) during the kernel-filling period, Plant Sci, vol.252, pp.347-357, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01363555

N. Amiour, S. Imbaud, G. Clement, N. Agier, M. Zivy et al., The use of metabolomics integrated with transcriptomic and proteomic studies for identifying key steps involved in the control of nitrogen metabolism in crops such as maize, J Exp Bot, vol.63, pp.5017-5033, 2012.
URL : https://hal.archives-ouvertes.fr/hal-01000350

L. C. Carvalhais, P. Dennis, D. Fedoseyenko, M. R. Hajirezaei, R. R. Borris et al., Root exudation of sugars, amino acids, and organic acids by maize as affected by nitrogen, phosphorus, potassium, and iron deficiency, J Plant Nutr Soil Sci, vol.174, pp.3-11, 2011.