Caracteriza??o funcional do transportador de nitrato OsNPF4.11 (OsNRT1.2) e seus efeitos sobre a efici?ncia de uso de nitrog?nio na variedade de arroz Nipponbare

• Ano de defesa: 2018
• Autor(a) principal: Arruda, Leilson Novaes
• Orientador(a): Souza, Sonia Regina de
• Banca de defesa: Fernandes, Manlio Silvestre, Cabral, Luiz Mors, Garrido, Fab?ola de Sampaio Rodrigues Grazinoli, Martins, Gilberto Sachetto
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Agronomia - Ci?ncia do Solo
• Departamento: Instituto de Agronomia
• País: Brasil
• Palavras-chave em Português: EUN; Nutri??o nitrogenada; Oryza sativa L.
• Palavras-chave em Inglês: Nitrogen nutrition; NUE
• Área do conhecimento CNPq: Agronomia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/4857

Nitrogen (N) is one the most required elements by plants, being constituent of the main molecules of biological systems. Therefore, large quantities are applied to the soil in order to maximize productivity. However up to 70% of the applied N can be lost by different processes. Reducing Nitrogen fertilizer input and finding varieties with a high nitrogen use efficiency (NUE) are the main goals of plant nutrition. Among the strategies to increase NUE, was proposed in this work the knockdown and over expression of OsNPF4.11 nitrate transporter in Nipponbare rice variety. For this purpose, after obtaining the transgenic lines were carried out three experiments in growth chamber and one in a greenhouse. In the root of knockdown plants, the high affinity nitrate transporters were down regulated, but in the leaves the opposite was observed, in the transgenic plants high affinity nitrate transporters were up regulated. Over expression of OsNPF4.11 also affected the expression of high affinity nitrate transporters. In the root (both low and high nitrate availability) and in the leaves (under low nitrate availability) high affinity nitrate transporters were down regulated. Both the reduction and the increase in the expression levels of OsNPF4.11 negatively affected the nitrate uptake, as well as the root to shoots transport, resulting in short plants with a lower total biomass. In addition to the absorption, changes in the OsNPF4.11 expression also affected the N remobilization to the grains, resulting in a greater number of sterile spikelets and a lower yield, and thus a lower EUN.