title: Phenotyping two tomato genotypes with different nitrogen use efficiency.
abstract: Nitrogen (N) supply usually limits crop production and optimizing N-use efficiency (NUE) to minimize fertilizer loss is important. NUE is a complex trait that can be dissected into crop N uptake from the soil (NUpE) and N utilization (NUtE). We compared NUE in 14 genotypes of three week old tomatoes grown in sand or hydroponic culture supplied with nitrate (NO3(-)). Culture method influenced measured NUE for some cultivars, but Regina Ostuni (RO) and UC82 were consistently identified as high and low NUE genotypes. To identify why these genotypes had contrasting NUE some traits were compared growing under 0.1 and 5 mM NO3(-) supply. UC82 showed greater root (15)NO3(-) influx at low and high supply, and stronger SlNRT2.1/NAR2.1 transporter expression under low supply when compared with RO. Conversely, RO showed a higher total root length and thickness compared to UC82. Compared with UC82, RO showed higher shoot SlNRT2.3 expression and NO3(-) storage at high supply, but similar NO3(-) reductase activity. After N-starvation, root cell electrical potentials of RO were significantly more negative than UC82, but nitrate elicited similar responses in both root types. Overall for UC82 and RO, NUtE may play a greater role than NUpE for improved NUE.
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy.
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Abenavoli
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Longo
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy. Electronic address: antonio.lupini@unirc.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lupini
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Miller
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Araniti
authors.affiliation: Institute of Biosciences and Bioresources (IBBR), National Research Council of Italy (CNR), Corso Calatafimi, 414, I-90129, Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mercati
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Princi
authors.affiliation: Dipartimento AGRARIA, Università Mediterranea di Reggio Calabria, Salita Melissari, I-89124, Reggio Calabria, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sunseri
mesh_terms: D057075:Enzyme Assays; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D018527:Hydroponics; D007700:Kinetics; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D008564:Membrane Potentials / Q000187:drug effects; D050901:Nitrate Reductase / Q000378:metabolism; D009566:Nitrates / Q000494:pharmacology; D009584:Nitrogen / Q000494:pharmacology*; D009587:Nitrogen Isotopes; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism
chemical_list: D009566:Nitrates; D009587:Nitrogen Isotopes; D050901:Nitrate Reductase; D009584:Nitrogen
keywords: Nitrate influx; Nitrate reductase; Nitrate transporter genes; Nitrate uptake; Nitrogen Uptake Efficiency – NUpE; Nitrogen Utilization Efficiency – NUtE; Tomato (Solanum lycopersicon L.)