Author(s)

Osmário J. L. Araújo¹, Milena S. Pinto¹, Marcus V. L. Sperandio¹, Leandro A. Santos¹, Elvia M. L. M. Stark¹, Manlio S. Fernandes¹, André Marques dos Santos^2*, Sonia Regina de Souza²

¹Plant Nutrition Laboratory, Department of Soil, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil.
²Plant Biochemistry Laboratory, Department of Chemistry, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil.

Four genetically contrasting rice varieties (IAC-47, Bico Ganga, Arroz de Revenda and Manteiga) according to Random Amplified Polymorphic DNA (RAPD) analysis were assessed regarding expression of the genes OsNRT1.1, OsNRT2.1 and OsNRT2.2 and the nitrate uptake kinetics parameters (Km and Vmax). Up to 250-fold increases in the induction of gene expression after nitrate resupply were observed for the high-affinity transporter (OsNRT2.1 and OsNRT2.2). However, no significant variations in Vmax among the varieties were obtained. The lower value of Km of the IAC-47 cultivar in relation to the Arroz de Revenda variety suggests a greater role of high-affinity transporter genes. These results indicate that closer attention should be paid to the expression levels of these genes in selecting varieties aiming to enhance nitrogen uptake efficiency.

RAPD, Nitrogen, Nitrogen Use Efficiency, Oryza sativa L.

Araújo, O. , Pinto, M. , Sperandio, M. , Santos, L. , Stark, E. , Fernandes, M. , Santos, A. and Souza, S. (2015) Expression of the Genes OsNRT1.1, OsNRT2.1, OsNRT2.2, and Kinetics of Nitrate Uptake in Genetically Contrasting Rice Varieties. American Journal of Plant Sciences, 6, 306-314. doi: 10.4236/ajps.2015.62035.